+1
If you want a cheap helmet cam setup get a Oregon Scientific ATC2K from ebay. They attach just about anywhere (including your helmet). They are self contained and waterproof. For $100 you can't go wrong.
ATC2K on eBay
There are a ton of sample vid's on YouTube - here is one chasing a FZ6 on the track...
YouTube - Fz6 Pista Franciacorta
YouTube - Broadcast Yourself.
Or
Better! You can go a better route, buy or use any digital camera that takes video (99% of all modern Digital Cameras do Video of some degree...) and mount it on your tank. You can use a custom tank mount (a guy on ebay makes them for dirt cheap
FZ6 Tank Mount
So if you already have a Digital Camera that does Video, or if you want to use an older miniDV or VHS-C video camera, you can use one of those...
I have a similar setup. I have a Tank Mount, but it isn't a dedicated one, it is the same thing that cop cars have to mount their camera on the windshield.
Here is what I have
Suction Camera Mount and it works FLAWLESSLY. I used it for over 20hrs of video during my ride up to Monterey for the MotoGP races this year... Here is a short video of Mullholland Drive in Malibu, CA...
YouTube - Mulholland Drive (at x2 speed) Yamaha YZF 600R R6
Any questions, feel free to ask... I have done a ton of homework on this stuff.