RESTAURANTS : Drinks and (a Cheaper) Dinner : The bar is becoming the busiest room in L.A. restaurants, as owners figure out diners are looking for casual, inexpensive fare

This is not the greatest time to be a restaurant owner. You don’t need statistics to prove the point. A slow drive down any street in town at 8 p.m. on a weekday night will tell the tale; as you peer into the windows of brightly lighted restaurants, you can’t help noticing that most are filled with empty seats.

There are lots of reasons for this, and not all of them have to do with the recession. Money’s tight, and most of us are eager to spend less of it, but we’re hoarding our time as well. A leisurely three-hour meal just doesn’t sound as appealing as it used to. Especially if you have to dress up to get ready to go out. And then there’s the planning problem: people seem to be increasingly interested in doing less of it. “I don’t feel like making a reservation . . . “ is a refrain heard all over town. “Let’s just decide where to eat when we get hungry.”

Smart restaurateurs listen to their customers. Which is why we are witnessing the sudden revival of the bar menu in upscale places. Don’t feel like a full meal in your favorite restaurant? Why not just sit in the bar and nibble? You don’t need a reservation, you don’t need to dress up--and you won’t have to mortgage the house to pay for it. Is it any wonder that the bar is becoming the most crowded room in the restaurant?

All kinds of restaurants are bringing back bar food--including some of the hottest tickets in town. Campanile--where reservations are still hard to come by--has empty tables in the bar almost every night. There’s no special bar menu, but you can waltz in, sit down, eat whatever you want and be out the door while the people with reservations are still waiting for their tables. Other restaurants, like those that follow, do have special bar menus; these three have have almost nothing in common--except that each is a terrific place for a small meal on the spur of the moment.

T rumps, 8764 Melrose Ave., West Hollywood. (213) 855-1480. Bar menu served Sunday 4 p.m.-11:30 p.m.; Monday-Wednesday, 11:45 a.m.-12:30 a.m.; Thursday-Saturday, 11:45 a.m.-1:30 a.m. Bar food prices, $2.50-$16.

Trumps is 10 years old, but it still has an edge. There’s something brash and young about all that noise, all that concrete, all that art. Right now people sitting at the bar trying to look beautiful have to stare down some serious competition; the walls are covered with portraits. Amazing portraits, uncomfortable portraits, portraits that demand attention. It’s hard to pay much mind to the maneuvers of the crowd around you with so much to look at up there. Is this guy ordering a single malt Scotch really interested in your girlfriend? That woman on the wall wants to know.

You won’t want to eat at the bar. You probably won’t want to eat at one of the little tables in front of the bar either--they’re much too low for comfort. But the tables beneath the wall of water that separates the bar from the dining room are cozy and comfortable and the perfect place for people-watching.

You can spend a lot of money--or you can spend a little. The menu is huge and deceptive. For $6 you can get some skinny little sticks of skewered chicken with spicy peanut sauce--and hardly feel that you’ve made a dent in dinner. On the other hand, you could order a pressed sandwich and spend $12 on a monster concoction of chicken, cheese, prosciutto and who knows what else that comes with a mountain of waffle potato chips. The canapes at $7 are silly, but there’s a serious plate of “BBQ riblets” that must once have belonged to mastodons; they’d be full-sized ribs in any animal of less massive proportions. Catfish fingers, at $12, are delicate, delicious--and for a single person provide a dinner of respectable proportions. They even come with vegetables.

In the finger food category there are vegetable wontons--little fried puffs of nothing that taste wonderful and vanish in an instant. There are those Brie and grape quesadillas that some people abhor and others adore (I tend to fall into the latter category). There is a mammoth bowl of shoestring onions that reminds you why you love fried foods and makes you wish that you didn’t have to feel guilty about eating them.

And then there are all the less serious dishes from the main menu. Those wonderful potato pancakes with goat cheese and apples. That great fried chicken. Tuna pastrami. Plantains and caviar. And lots of desserts. The peanut brittle sundae--a giant joke of a dessert--is sweet and salty at the same time, easily feeds three or four people, is terrible for your teeth and is a completely satisfying way to end the evening.

The Trumps menu is so big and so lively that you tend to order a little, then order a little more. But you could do this quite a few times--and still not spend half of what you’d spend on dinner in the main dining room. And have a lot more fun while you are doing it.

J immy’s, 201 Moreno Drive, Beverly Hills. (213) 879-2394. Bar menu served in the lounge; full menu served there as well, Monday- Friday, noon-midnight; Saturday 5:30 p.m.-midnight. Bar menu, $5.50-$16.

If Trumps works hard to maintain its edge, Jimmy’s does the opposite. This is a place where people come to relax, to forget, to pretend that they are younger than they actually are. Most nights you will find a group gathered around the piano, drinking, flirting--actually singing along with the man at the keyboard.

It’s not the best place in the world to have a meal. In the lounge itself the tables are at knee height, so you have to sort of bend over to eat. Upstairs there are a couple of tiny tables, but you’re right smack dab in the middle of the path to the dining room. This also puts you next to the dessert table, so you have to watch as the tarte tatin , the best dessert in the house, dwindles as you sip your martini. If you are in the mood for sweets, ask your waitress to save you a piece.

What to eat here? Skip the $16 steak burrito--unless you love knowing that there is some guy back in the kitchen wondering why you’d be willing to pay so much for something that you could get so much better--and cheaper--off of any taco truck in town. This is a place for the classics--things like oysters, Caesar salad, poached salmon and steak tartare. It’s the right food for the music. And if you sit here late into the night, you’re almost certain to see some celebrity come walking in. It’s happened every time I’ve eaten late dinner in the bar.

P azzia, 755 N. La Cienega Blvd., West Hollywood. (213) 657-9271. Bar menu served in the bar and the courtyard. Tuesday-Sunday, noon-2:30 p.m. and 6:30-11:30 p.m. Bar dishes, $4-$9.50.

The best bar in town to eat in at the moment--and the one with the most comfortable tables--is the one at Pazzia. They call it Pazzeria; I call it a pizzeria with class.

The pizzas are the heart of the menu, and they’re so good that I find myself thinking about them every time I am served one of the lesser pizzas in town. Assertive toppings are slathered across crunchy, paper-thin crusts. The Napoletana is simplicity itself--just tomato sauce, mozzarella and anchovies, but each bite explodes in your mouth with a burst of flavor. Another of those crispy discs comes covered with ricotta cheese, grilled radicchio, black olives and pine nuts, a perfectly balanced combination that gives each ingredient its due.

While you’re waiting for the pizzas to come out of the oven, order a plate of antipasti misti , absolute perfection in bar snacks. The plate changes from time to time, but usually includes a couple of little balls of mozzarella, some goat cheese with olive paste, grilled peppers, a piece of prosciutto, marinated octopus. . . . You might want to augment it with a plate of salty, thinly sliced meats--rosy petals of buttery prosciutto, thick chewy slices of air-dried beef ( bresaola ) and pungent hunks of salami. With a slice of their good bread and a sip of wine (sold here by the carafe), this is almost as good as being in Italy.

Pasta here is the real thing too--the strands cooked only until they are chewy and then lightly mixed with sauces that get their punch from quality instead of quantity. I especially like the tagliolini with clams, although the fettuccine with polpette-- airy little meatballs constructed from bits of veal--is a close second.

There’s a fine salad of mixed greens topped with slabs of Parmesan shaved so thin that they seem to have blown over on the latest wind; the dressing is olive oil, balsamic vinegar and shallots, and it’s as good as a simple salad gets. You can finish the meal with a dish of gelato and a really good espresso.

When you get the check it is a mere fraction of what you’d pay for dinner across the courtyard in the restaurant itself. Nothing on the menu is more than $9 and a couple can get out the door, with wine, coffee and dessert for about $40. Which brings up one important question: with food this good in the bar (and on the patio), who is going to spend three times as much money to dress up and eat in the restaurant?