Don,

I use my M-Audio USB Quattro live with the laptop. The sound quality is quite good. I think they were going for as low as 125 Usd at one point.

The big disadvantage of course is that it's an external box ( about 5 " wide, 1 1/4 " tall, 4 "deep ). This doesn't bother me at all, but I can see where it might be more desirable for a live performer to use an internal soundcard. I like that it has 4 inputs and outs though, because it also allows for me to make my laptop a portable 4 track DAW. I bring it when I go to my guitarist's place and we can record ourselves on seperate tracks.

AJ