Here are some psych-talk style approaches to relabeling "atheist"...
Theistically uninhibited
Rationally focused
Evidence dependent
Belief challenged
Sense obsessed
I might like to be called "deity free", except it sounds a little smug (but not nearly as bad as "bright"). From many believers' points of view, the very concept of atheism is smug anyway.
The biggest problem I have with the label "atheist" is that I hate being painted with such a broad brush. If you call yourself "Christian", you can refine yourself a little further by naming your denomination, church, how often you go, etc. You can't say much about your worldview with "atheist". Whether atheist or Christian, you might have a very different worldview than the next guy in your group, with little in common beyond your (non-)belief in god(s).
Renaming atheists seems like a losing game, but maybe the term can be refined by spinning off a sect, so to speak: The "anti-theists". One of the worst things about self-identifying as atheist is that I'm sometimes associated with the militant, God-hating, head-up-the-ass variety - the fundamentalists. I haven't met many, but they can be just as obnoxious as the Bible-thumping fire-and-brimstone crowd. I'd like to distance myself from them, in the same way that I'm sure some Christians want to disavow their kookier cults.
It would be nice to make a further linguistic split between gnostic/agnostic atheists (atheist/nontheist?), but I don't see it happening, except by some whim of culture.
Edited by glowby, : typo: missing word