I have the Black Cat on one of my keychains, and I like it (thank you Boaz). Be sure you get it with the white light, as they make it with a red emitter as well and sometimes you think they are referring to the body of the light, when they mean the beam.
The Black Cat has a very focused beam, BTW, kind of throwy for a small light.
I have all three of those lights and I like the 703 the best, it has the brightest tightest beam plus it works awesome with aaa batteries so no need for 10440s.
Im with Confusius on this one. The tank is brighter, my wife has one that she loves. Its a very nice little light. The skyray he mentioned is a great little light. My daughter has one on her keychain. It is very small, not as bright as the tank but still brighter than anyone would expect from such a small light. They are both nice and I would have a hard time choosing. The skyray is just a tiny bit longer than the ITP EOS but it is skinnier. Feels smaller overall to me.
You might also consider the "real deal" photon for that price.
The problem with the cheapo chinese lights is that there's always the risk it'll fail due to some crap QA (or the crap spelling on the black cats), so unless they're close friends, giving someone a light that craps out in a week is not a good idea. That's why I'm leary of giving anything but romisens. Tank007 is also one of the better ones if you're going to do it.