Reader Matthew kindly sent us a tip (thanks!) that the TV Shows section of iTunes is currently featuring a five page listing of free television episodes available for download. As you might expect, lots of it is junk-- apparently Scott Baio has another television show, and someone thought it was a good idea to call it "Scott Baio is 45... and Single," but there are some shows worth watching in there, including a BSG wrapup (hey, gotta watch something to hold us over), a few Gray's Anatomy shows, and the pilot of Jericho (those are all iTunes links).
So if you're looking for some free quality video (or just something to play on your iPhone for that trip you're about to head out on), looks like the iTunes store has it.
Update: Our commenters also point out that there's lots of good free TV hidden in iTunes' podcast section as well-- two episodes of Flight of the Conchords is much better than anything you'll see highlighted in the free section.