Dang....already.
 

Has not even been 24 hours and I already lost the lens cap for my new XL2. Left it at the park, went back. it was gone. Anyone know if they sell them in packs of five? Maybe a family pack of 20?

Replacements are available from Canon USA. Call 1-800-OK-CANON and cycle through the menus until you get to Parts & Service. Back pockets were made for lens caps, by the way.

I think Sony was onto something with their new integral lens covers on the PD-170 and Z1. They're like hinged louvers which flip open inside the lens shade. Very handy....

But on all my other still and video cameras, I've gotta agree with Chris: that's what back pockets are for. Just be sure to blow out any lint or dust that may have been picked up before capping the lens though.

Adam,

I took the advice of a very sage DSE: put sticky velcro to the top of the lens shade and on the lens cap, then always put the lens cap on the velcro when you remove it from the lens to shoot. If you forget to put it back on at the end of the shoot, it's stuck to the lens shade which is hopefully still attached to the lens/cam (otherwise the missing lens cap is the least of your worries).

Black velcro blends with the lens shade and lens cap so you almost don't notice it. For more adventurous types, grey and red matching the XL2 body might be stylish (or garish, i wouln't be able to tell with my lack of fashion sense).