Hi,
I do some amature DJing playing favorite tracks without really mixing and beat-matching. Mixing beer and vodka doesn't count I guess. But I'd like to pre-remix some older tracks using fresh beat loops and samples. What software or what kind of software do I need? Preferably something that's easy to use. I'm on G4, 450Mhz. Thanks for your help.

Ableton Live is prob. your best bet for doing re-mixing / mash-ups.

Thanks, I'll check it out. I thought it's supposed to be used Live. I don't need it for Live DJing, I don't have a laptop, I use CDJ combo.

Live is pretty much close to a full on DAW like Logic or Pro Tools. It is also a useful DJ tool for remixing - you don't need to use it in a strictly live environment - you can burn your remixes to CDs & work in a way you are comfortable with. If you gave Live a try though, you may find yourself bringing a laptop to gigs in place of the CDJ.