I just bought a Solitaire Saturday -- the red ones (only red) on sale at the tractor supply store for $3.14. It's terrible as a flashlight, but very pretty to look at, and even fun to take apart (after I decided not to just leave it in the original package). The one advantage it has over my other low-level keychain lights is it can focus the beam so it can light up something a few feet away better than the little ROV or Dorcy, but in practice I'd just use another light for that (like my 45 lumen Dorcy AAA). But hey -- it's a piece of art.
The other though I had is put some aluminum foil up against the bulb section, remove the o-rings, and use it to stash my half-smoked cigarette in when I'm out and about (yeah, giving up smoking, again -- but at the price of even roll-your-own I'm not going to waste a half a butt). It makes a nice little storage container. You can put toothpicks or some pills in it.