I Have a Toneport GX, cost nearly nothing, fun for a weekend, but now i dont use it anymore because it has nothing to do with sound just with bits and bytes, YES IT BYTES!!!!!
The thing that put me off most is the software that you get with it, its 'free' for a couple of months and then you have to buy it to use, at least the whole package. The software that remains usable consists of a handfull of digital effects and a jack to usb converter.
Still hoping i come across some decent usb active mic, audacity is fine to get some basic stuff recorded.