Just to digress to the original subject (Linux on an Intel Mac with no OS X partition)...
If you didn't mind reinstalling Windows (yes, having to do so would suck), you have the option of simply blowing away your hard disk and starting over with your Windows XP and Linux installation CDs. (Traditionally the "easiest" way to set up a dual boot is of course to install Windows first and then install Linux, as current Linux CDs are smart enough to detect/resize/incorporate into GRUB an existing Windows partition.) Why would you want to do this? Well...
Prior to the introduction of "Boot Camp" and an accompanying series of firmware updates Intel Macs *required* GPT-partitioned hard disks and EFI-aware bootloaders. (Many of the "Linux on a Mac Mini" Howtos you'll find out there were written in 2006, when going through such hoops were necessary to install anything besides OS X .) However, assuming your Mini is up to date the firmware should now have a built-in BIOS compatibility mode allowing it to boot MBR-formatted disks just fine. Currently your "bootcamp-ed" hard disk has a "hybrid" GPT/MBR partition table, which is the source of the remaining "complexity" in multi-booting OS X alongside other OSes with "legacy" BIOS bootloaders.
If you were retaining OS X on the disk then
rEFIt is about your best choice for a boot menu that can "chain-load" OS X, Linux, *and* Windows. But since you want to get rid of OS X, well... if you blow away your existing data and reinstall from scratch the Windows (or Linux) installer will create an MBR boot record on your hard disk. That will cause the firmware to load the BIOS compatibility module automatically, and let you use regular GRUB/Lilo instead of an EFI-aware solution. Which means your Mini will behave basically just like a plain old PC, no extra fiddling. (There are advantages to this other then simplicity. For instance, until recently at least the GMA950 video driver in Linux had issues switching video modes "natively", so it would default to making legacy BIOS calls. If you boot with elilo said BIOS isn't there. There are several drivers in Linux that have similar teething problems... mostly video drivers that don't apply to you, but it's worth noting.)
Anyway. When I installed Linux on my work Mac Pro (boo, hiss, I know) the BIOS compatibility mode had just been integrated, so I originally did it by simply yanking out the factory-formatted primary OS X drive and doing the installation on the second drive, MBR partitioned. And it "just worked". However, it is worth noting that in the end I ended up putting the OS X drive back into the case and setting up rEFIt anyway so I could have the option of booting into OS X to apply firmware updates. (The original 2006 Mac Pros shipped with some *nasty* bugs in their BIOS emulation, and there was also a bad ATI video card BIOS bug that prevented the card from initializing properly in legacy mode about half the time.) Seems kind of a waste to dedicate a drive to a firmware installer, but... eh.
