The Foldylock has a funny name but it's serious about protecting your bike.
The 3-foot-long device is made up of six quarter-inch-thick hardened steel bars linked together by heavy duty rivets that allow the bars to fold and unfold in their sockets.
The two end pieces lock into each other by an integrated sliding deadbolt mechanism with a proprietary key. Unlock, slide out the "male" end piece, wrap the bars around your bike frame and a secure stationary object, then slide the end pieces back together, lock, and you're set.
The bars fold into an 8-inch-long brick that slides into an included rigid rubber holster. For transport, the holster can be attached to a bike's bottle holder screws (extra screws included), or secured to the bike frame with two included Velcro-sealing straps.
The Foldylock weighs in at nearly 3 1/2 pounds, so you won't be toting it around in your pocket between rides.
Info: Foldylock in green, red or cream costs $95.