After looking at some designs by Nerk & a few others, concocted a new over the over the shoulder mount on the weekend...
Hasn't been a good swell for the SUP yet, but here's a couple photos from using it when kitesurfing...
The view is awesome .. when watching, it really does feel like you're looking over the riders shoulder. 
Really easy to build .. less than 1/2 hour if you have the bits laying around...
Parts:
- old camelback
- two cable ties
- bit of polypipe
- plastic clip
- keyring
- gopro tube mount
(The green tape/cloth is there to soften the sharp edges of the tubemount/screws)
I hook the bottom clip to my harness when kiting, but am guessing I'll need a belt or something to keep it "upright" when surfing
Unit is so light, easy to forget you're even wearing it.
Enjoy.. 
Nice.. I've been meaning to try that idea for a while now.. Did you get any vid?
DJ
Sure have Dave, but haven't had time to process it/upload it as yet...
For the inventors out there, a few other "home made" designs here:
www.seabreeze.com.au/Articles/Kitesurfing/Filming-kitesurfing-over-your-shoulder-with-a-GoPro-HD_4602204.aspx
It would be funny if you were the kind of person who hated people looking over your shoulder.
Being irritated for a few seconds when you are on the computer or reading the paper but imagine how fuming you would be after filming on the water, editing the footage, sorting through the photos and making a 3 or 4 minute vid.
You'd be ropable[}:)]
By the way its a great idea I like it
