My band and i have been on the hunt for the better part of a year for a device that will just record audio of us playing. weve tried several things and absolutely NONE of them have been worth a damn. until now. FLIP VIDEO makes a recorder that is worth every penny. not only does it record high quality kick ass sound, but also HD video! I HIGHLY recommend this gadget
heres an example below, I edited the clip on my phone so the video is lesser, but he sound stays the same. (our intent) oh and im not asking for a critique, the rest of the band was smoking outside and we were just "staying warm"
you'd get crisper results with a mic-mixer/interface setup. I've got a kel hm1 condenser mic and a focusrite saffire 6 usb interface and, when I get the distancing/levels right, it can sound like an unmastered studio recording (obviously...it hasn't been mastered yet). And it is pretty portable -- I carry it around to jam sessions with friends sometimes. Maybe, if you want to record an entire band in one take, you might want to get a dynamic mic, as they are best suited to recording live shows, are inexpensive, and are probably more more durable than ribbons and condensers.
this may or may not be useful, I'm not sure. I suppose of you want video and not just audio, then...alternately, you could just run the audio setup while you film so that you get a better audio track.