I cant even begin to tell you guys how useful Find My iphone is!
Yep... I usually find my wife's and then tell her where she left it last
OMG, I left mine on the light rail one morning, and watched it on Find My iPhone go to the terminus of the line. Called the light rail operator and they assured me that the driver would probably find it while he swapped ends of the train. They had me meet the car on the way back down the line and got my phone back! Phew!