Find out what digital stations you can get with just an antenna and a new TV (or other ATSC tuner, like a TiVo HD) here.
Today’s Woot is the Pinnacle HD Pro Stick; I can attest that I have one of these and it’s pretty cool. Presumably Elgato’s EyeTV, which works really well on my MacBook, is bundled with the Mac version—the PC software is pretty lame, in my experience, but maybe they’ve figured out the crashing problems it had. It also works under Linux with the right patches—not sure if they’ve made it to the latest Linux kernels yet or not.
So, check to see if you can get some HD television over the air, and if you can then pick up one of these babies. If you miss the Woot deal, you can get it (or the more Mac-happy Elgato model that’s basically the same, but lacks an antenna and includes the full version of EyeTV) at Amazon.com instead.