<img src="http://tctechcrunch2011.files.wordpress.com/2007/01/antenna jacks, but also Freeview HD and digital satellite inputs. In addition, it has specialized software to automate recording of your favorite broadcasts and a TV-style remote control to operate the whole shebang.
It's mostly only of use to our friends in the UK, their TV systems are very different than our own. That being said, if you're in the UK and in the mood to brew your own mega PVR, go get it.
WinTV-HVR-3000 [Product Page]