I have a succession of action cams... best to get a secondhand Go Pro off
eBay if you want one.
Personally I prefer a head cam with a cable to a unit that allows you to frame up stuff. Like this video here shot on a Dogcam Mini DVR HD
View: http://vimeo.com/46219682
. There used to be a few available but only the VIO from dogcam seems to be remaining and that costs 500 quid. The Mini DVR has an HD record time of over 3 hours, so I just set the cam up and leave it on... edit later. Ideal for action sports.
I would recommend you get a good camera though, whatever brand it is, consider that memories are priceless... and likely unrepeatable.