The Null Device
Good news for audiophilic Penguinheads: I've just discovered that Linux (2.4.x, anyway) works quite well with USB audio devices; which include studio-grade digitisers and such. (Given that USB audio is a standard protocol, unlike high-end PCI cards, means that they don't need special proprietary drivers for which there's no Linux market; which means thay you can now MP3 your live concert tapes/rare vinyl without incurring consumer-soundcard lossage.)
I just got my hands on a Egosys U2A USB/audio box, and it works under Linux. I just have to figure out how to select inputs (the default seems to be one of the digital ones). Oh, and licq sounds funny as the box doesn't do sample rates below 32k or so.