Webcam video usb storage

Hello,
I have to advise a series of video presentations on a somewhat small budget.

Basically I want to send each presenter (by mail) a camera+storage device so the video collected will not take up any of their hard drive space, nor be dependent on the computer. Has anyone had success with a device which records video into an external device. (Not a traditional camcorder, as it should be digital).

Max $200.

Thanks in advance.

Also to add: those little "spy" mini-cams look like the quality will be alot less than needed. The needed quality will hopefully be closer to 30 fps, 600px+.