Dual core IMAC24, resizing the partitions

Have a 250gb hd, running OSX and XP under bootcamp, very happy to report that I used a free pre release version of Camp Tune to successfully increase the XP partition by a substantial amount, I even took the risk of not backing up anything

http://www.paragon-software.com/home/camptune/free_download.html
I downloaded the image, burnt a cd, rebooted the cd under OSX and followed the instructions, took a while to initialize, dos style interface, just remember to know how to eject the cd when complete, holding down the mouse when rebooting worked for me

The older way is much more complicated
http://dustyreagan.com/how-to-increase-or-decrease-your-boot-camp-partition/