Up until fairly recently, the possibility of streaming media on cell phones in the US was not really likely - however Sprint now thinks they have cracked it.
In a join venture with Samsung, Sprint will stream 15-frames/second video as well as audio directly to the Samsung MM-A700. The kind of content available is much as you'd expect - sport, weather, news, etc.
Alternatives, such as the Idetic MobiTV, are not as cool. Idetic MobiTV lays video clips faster than the 1 frame per second, for example, and requires the user to download the entire video to the phone before playing it. Sprint's offering will be purely streaming.