NewTeeVee has an updated summary of where the broadcast television networks are airing their new tv shows for free. If you miss the show on TV, and don't have a DVR, you can now catch most episodes streaming for free on the web. NBC is even offering free downloads, eventually to be available for transfer onto portable video players, for one week after each episode airs.
You can also watch most of these shows via the desktop browser VeohTV, which I am a big fan of.