Canon at one point sold these little 300mm/400mm Image Stabilized Lens Replica Keychain LED Flashlights which quickly sold out. I managed to track one down for my random collection. The Flashlight is only about 2" long and 1" wide with a single LED bulb. There are no on/off buttons to manage the flashlight. To turn on/off the flashlight you'll need to turn the lens body which seats the battery connection inside. On the side of the lens is the keyring which includes a Canon charm (opposite side stays 'Image Stabilized').
If you're not up to speed, I seem to collect random camera related things, especially Lens Replica Mugs. They are fairly cheap and trust me, they make 'EXCELLENT last minute gifts' if you have them laying around. It's just something nobody wants to throw away. For those who share the same hobby, here's a look at the latest Canon 70-200mm F/2.8 IS version. I have the original 70-200mm F/4 IS mug which wasn't exactly like the real lens, but this version looks pretty close and it's offered with stainless steel insert for hot beverages. The one that looks 98% exact would be that Canon 24-105mm.
One tough item to find lately is the Canon 300mm/400mm F/2.8 Lens Replica High Power LED Keyring Flashlight. Originally offered by Canon a few months ago and now sold out everywhere. The only person in the country who's carrying it now is this one eBay seller (click here)
Canon Lens Replica KeyChain LED FlashLight
For Canon Replica Lens Coffee Mugs, the good ones are the 24-70mm F/2.8, Canon 100mm F/2.8 IS USM Macro, 24-105mm F/4 IS, 70-200m F/4, and 70-200mm F/2.8 IS. Check out all the other articles about other lenses in the collection here: http://cheesycam.com/?s=lens+mug+replica