Basically a Freeview TV card with twin tuners, meaning that you can watch one channel while recording another. You will need a desktop with a free PCI slot, though.
Comes with a remote and two teeny aerials, meaning that (in theory) you can use it right away. Though of course that depends on your location and where you decide to place them.
Cheapest price I can find elsewhere is £66 from ebuyer.com. Worth a go if you can find one.