For my birthday back in January my wife decided to give me a coffee cup/travel mug replica of the Canon 24-105mm f/4L IS USM zoom. As you can see from the accompanying photo, you would have to look closely to realize that it is not a lens. With the exception of the word "Canon" it has the same design and dimensions as the real thing.
If you were to pick up up you'd immediately know from its light weight that something was amiss. Instead of lens elements it has a styrofoam-insulated interior with a stainless steel inner liner. The "lens cap" is actually a press-on lid that fits into the inner diameter of the cup. There's enough room inside to hold 8 ounces (250ml) of liquid without being full to the brim. Linear distortion, vignetting, flare and chromatic aberrations are all non-existent. Then again, so is its resolving power.
So far so good; however, should you be so optimistic as to try using it as a cup you'd discover that the lens cap/lid is far from leakproof. Any liquid inside that splashes onto the rim will leak out and drip onto the outside. I'm not talking a few drops here; I mean enough that the lid is practically useless. Even it it were leakproof, the lid has no hole, so you'd have to take it off anyway to sip the contents. And even if this replica functioned perfectly as a coffee cup you'd have to question the wisdom of leaving it in your vehicle, in plain sight of thieves who would see only what looks like an expensive lens.
In short, a travel mug this is not. It's fun to look at though. You might also get a few laughs from yelling "Catch!" and tossing it across the room to your photographer friends.
If you're interested in getting one of these for yourself or someone else, they're widely available on web sites such as this one. Nikon lens versions are also available, as well as 70-200mm zoom-sized thermoses. Prices start at $40.00. That's a bit high considering the marginal quality and functionality of the product itself. On the other hand, if you're shopping for yourself or the photographer who has everything, you won't find a better price for what looks exactly like a $1250 Canon 24-105mm f/4L zoom.