Say you want a cheap flight from Manchester, England, to Greece, but you don't know which budget airlines or charters fly there. Turn to www.whichbudget.com, which offers a directory of such carriers around the world.
What's hot: The England-based site lists 116 airlines in 124 countries, including out-of-the-way nations. Perusing is fun just to find airlines you never knew existed.
What's not: From L.A., it lists Southwest as the only budget carrier to most domestic airports.