i was at the beach the other day and we were goofing around... i put down my camera in the sand, and then thought it would be a good idea to catch-in focus this squirrel that was begging us for food, by putting some food on top of the camera and "camouflaging" it in sand... of course, the 18-55 didn't fire the catch in focus, i can't remember if it only works on certain lenses or if i had a wrong setting, but this iphone pic shows the squirrel eating and what not to do with your equipment.
thought i'd share.
fyi: do not try this at home, sand got into the e-dials as well as the flash pop-up hinges... though after running the camera under the faucet and turning the wheels a full 360 the sand came out. as for the 18-55WR, it actually seems pretty "dust resistant" as no sand got into the focusing or zoom rings, they both turn as smooth as ever (as smooth as the 18-55 gets anyways)