For those who want to dual-boot an existing Vista installation with a Linux distrubution, the secret is to install GRUB onto your linux boot partition and not into the MBR. Then, boot into Vista and using EasyBCD add an entry for your Linux distribution. You can then multi-boot using the Vista bootloader. I've currently got my home machine triple booting into Vista (my day-to-day OS), XP (for games) and Ubuntu (for specific dev work)