Interesting thread as I've just started experimenting with this sort of thing....
I've got a POD X3 USB'd up to my laptop that could potentially record bass/guitar/vocals but clearly not all three at once.
Just begun using a program called Audacity to record and edit and after a POD firmware update it records via the usb fine. It seems fairly userful but I'm still learning it. Its free which is the best part: (
http://audacity.sourceforge.net/)
The POD has built in MIC Preamps which can be tweaked so I'm hoping my cheap microphone won't sound too bad.
early days yet...