Ableton live is a tool that Ive played and toyed around with for a while. I found out about it more towards the end of my DJing stint. I wish Id started off with it...
Its a tool that will let you compose and rewrite your tracks live in real time.
If your a writer, composer, a DJ and you wish to sample during a live set or presentation then this is undeniably supreme. Geared more towards live sets with the emphasis on your sets being LIVE, this will allow you to control the way you present and compose your music/samples/beats on a live stage with minimal fuss. Id recommend a look at the very least. With people like Chemical brothers backing this application who could question its ability.

http://www.ableton.com/free-trial

Or you could download from these...

382 MB
http://rapidshare.com/files/218880923/A6leton.Live8.801.GRB.part1.rar
http://rapidshare.com/files/218866853/A6leton.Live8.801.GRB.part2.rar
http://rapidshare.com/files/218862321/A6leton.Live8.801.GRB.part3.rar
http://rapidshare.com/files/218839246/A6leton.Live8.801.GRB.part4.rar
or
Part 1) http://www.megaupload.com/?d=0WF64WIW
Part 2) http://www.megaupload.com/?d=KNRWC0CZ
Part 3) http://www.megaupload.com/?d=2MIRHKAW
Part 4) http://www.megaupload.com/?d=INOGCS3G