There's app called tv.com, it has alot of shows on it from major networks, and i've had no problems watching it over the 3g network. Check it out.
can you access hulu.com on it? i use that to catch up on network shows that i missed during the week.
You do know you can go to NBC's mobile site and watch full episodes on your phone right? No app needed no flash needed. The shows are split into multiple parts, but I was watching some circa 1978 Battlestar Galactica earlier today.