Another Vote for Zoom or similar recorder. And don't just use it as a USB microphone - one of the best things about it is that you can take it to the place where your music sounds best (and in the same rooms as a computer with whining fans is unlikely to be that place) Also you can record live events away from home with it, in good quality stereo.

Edirol, Olympus, Tascam, Sony and others all make portable recorders too. Shop around. They are all pretty good.