Well, it looks like it's about the same size as my 40Gb iPod (just slightly smaller). And about the same size as the Archos gmini -- the Archos has a camcorder in it, though, which is kind of neat. I've enjoyed the low-quality video that my camera takes, and the Archos would be a (small) step up from that plus music (though as a camera it sounds like it's about cellphone quality).
The Amazon reviews make it sound like the iAudio is a more polished product. But then, a lot of the complaints about the Archos are about features that the iAudio just doesn't have. And the Archos is actually cheaper (though it's sale price at Amazon does make me wonder if there's something wrong with it). Oh, though the iAudio has FM radio, which is nice.