Video recorders continue to get cheaper and smaller. A popular packaging is to combine a USB memory stick with a tiny camera. For example, the Stunt Cam and the Sinykon 65125. For around $25, you can clip one of these little cameras in your shirt pocket and record away for hours (it sounds like the battery will die after a couple of hours, although the memory of the Stunt Cam can hold 33 hours of video).
Sinykon markets their camera as a “spy pen camera” so I want to make clear that we do NOT advocate spy recording. I’d like to wear a camera like this to capture, say, a walk around Fisherman’s wharf in San Francisco. Mike Bukhin has a neat idea for warning people that he is taking pictures (he has his cell phone programmed to regularly snap pictures and upload them to a server). Mike has a pocket sewn into his hoodie with a hole for the camera, but, far from being a surreptitious, he puts a picture of a Camera on it to draw attention to what he is doing.