CBS Interactive is a free app that AppleInsider says is the first iPhone app in the U.S. to provide free streaming TV content directly from a studio. The app streams content from TV.com, which has a limited selection of CBS shows, including the "Late Show with David Letterman," "CSI," and "The Young and the Restless."
Customer reviews are all over the place, with some saying it doesn't work and others saying it's great. Even if it doesn't work now, you know that it'll get better. And undoubtedly the selection will improve, too. I haven't tried it yet, since I don't have 3G.