I bought this last week

http://www.sports-cameras.com/extremetwo.shtml

It will be here hopefully next week. It's about the size of a sausage, tiny and produces pretty good quality video (not as good as dvd however). It's wireless and has a small receiver which records the video. The transmitting distance is around 500m which isn't great, but what I will do is get one of those waterproof bags that they use for walkie talkies and stick in my pocket. I guess I'll either attach it to my boom (clew end) or maybe top of mast? So should be good!