Leon, I think a combo of the two would be the ultimate in my situation. I like others posts here about using a laptop (as I think the 'industry' will likely gravitate toward developing add-ons and such for the performer(s) who have a laptop handy). And, as MIDI is truly the digital version of our acoustic world I think the PC will likely be THE platform by which product developers get their product(s) to musicians. But, I think the your idea of using an MP3 is right on too for two reasons:

For one, when we go to audition for a gig, having an MP3 with various backing tracks would work easier -- just plug it into the 'house' system and away ya' go! If the guy/gal wants a 'live' audition (without my setting up the whole band), again I plug in the MP3 to the house PA and hop up on stage and perform a line or two against another track (perhaps one without my solo for example).

And then secondly, when we do set up for the live performance, we plug in the laptop and run the backing tracks from there. If we as a band, want or need to change the show format, we're set to do that. And, if and when something goes wrong (i.e. PC breakdown), we have our selected performance WAV's saved to the player. On the other hand ... I could create a music DVD with these on it and this would work just as well even without the MP3. I suppose there's a dozen more ways to skin this cat!

I think I'd kinda' like the MP3 thing myself because I see myself (as well as others in the group), listening to our practice session cut during the days leading up to a performance. Kinda' self critiquing ourselves I guess.

Thanks again Leon!

Ike