Most of the solutions I've seen are computer based. Standalone recorders were available from Sony and Toshiba, but they were wicked expensive and most, if not all, have been discontinued.
The cards with the best software support seem to be the Hauppauge brand. Here's a link to their digital cards: Hauppauge Computer Works: Compare WinTV-HVR ProductsComputer based is ok too, any reccomendations on a brand/model for the computer card?