I'm generally satisfied with the Ion Speed Pro. It's weatherproof as-is. Shaped like a fat tube, similar to the Contour Roam. Reasonable price, around $60-$75. Runs about 90 minutes per charge. Doesn't include the Ion made helmet mount but I rigged up my own from one of the spare mount shoes, some heavy duty Velcro tape and zip ties. Has worked fine for a year, about 50% on helmet (when riding my errand bike and hybrid), 50% on the standard handlebar mount (on my road bike -- the helmet mounted camera would only record the road when I'm on that bike).

I've written more detail on the pros and cons elsewhere on various bike forums threads.

Sunday evening was one of the few times the past year I didn't use the camera, and one of the rare occasions when I was nearly hit by an inattentive driver, less than 200 yards from my front door. Seems to be the way these things go. Fortunately I'm more attentive on my own block, which has the worst drivers in town. While I don't let my guard down elsewhere, I don't quite feel like drunken rampaging crashmobile pilots are as big a worry elsewhere, as they all seem to live in my neighborhood.