Focusrite Saffire LE firewire external soundcard here. Works really well with Vista 32bit - sound is really excellent, with excellent preamps. It replaced an internal/external M-Audio Delta 66 - also excellent - but it had no physical gain / volume controls, only software ones, and when the Saffire came cheap (as it was being replaced by the manufacturer) the Delta had to go.

If you are looking just for a USB sound card to replace a poor quality internal one and aren't too bothered about only having phono ins/outs, I heartily recommend the Behringer U-CONTROL UCA202 - it sounds absolutely first class as a laptop soundcard replacement. I use it with my laptop to stream i-Tunes tracks from my office PC via wifi to my main hi-fi in the lounge. It costs about $30!

Brian