Keep trying.......
I imagine it's possible to tether, but I've searched for an app, and have been unable to find one. I checked with developers, and found the cost prohibitive, even sent the idea to an entrepreneur feeling that I'd rather see it created and let someone make money off it just so we could tether.....it's a great idea, what portability it would offer! Please post if you find an app that I couldn't find, or you find someone willing to develop it.