This is what you want:
http://cgi.ebay.com/SONY-Handycam-DCR-TRV18-MiniDV-Digital-Camcorder-L-K-/330454307495?cmd=ViewItem&pt=Camcorders_Professional_Video_Cameras&hash=item4cf09c92a7
When you're out shooting, time is of the essence. You're going to be working with volunteers, and it's not cool to keep them forever and ever. They'll only stay so long. So, you're going to want to get as much done as you can, in as little time as possible.
The pocket cams are not made for this kind of thing. They're made for people who want to get good video, while carrusing out on the town with their friends. They're not set up to allow you the kind of control you're going to want on a set.
Here are the big issues:
Focus ring, and exposure dial. The camera I'm suggesting has both. Pretty much all cameras these days offer manual focus and manual exposure (I think they do, anyway). But on the camera you're looking at, it's not going to be nearly as easy to adjust them as on the used camera I'm suggesting.
You don't wanna be fidgeting with awkward menus and touch screens. You're going to want the controls right at your fingertips. You're going to want a focus ring and exposure dial. With these two items, not only will your shoot run more smoothly, but you'll have more fun, as you won't constantly be messing with these little annoyances.
You're also going to wanna make sure to have manual white-balance (but that's pretty common) and an audio-in jack (also common).
Look at that price! I think it'd be a good idea to snatch this one up. You would normally have to spend somewhere around $250 to get a used camera with a focus ring. Most of them make you use a touch screen, or a stupid little incrimental button. You definitely want the ring.