I thought I'd share the details of how I successfully managed a "non-standard" installation of Boot Camp in 10.5. Basically, I wanted three partitions on my startup drive: System, Users and Windows. (I don't want a debate on the merits of partitioning; it works for me, and the one time I didn't do it, I lost a ton of stuff due to 10.1 weirdness).
So, Boot Camp Assistant will not allow this. Full credit for the workaround goes to AxL over at Apple Discussions. I just tweaked the original a bit, and included some additional details. Read on...
Assuming you're all backed up, and ready to wipe your disk, here's how to do this:
- Start up from the Leopard CD
- Don't go in to the Installer when it appears, instead launch Disk Utility from the menu bar.
- Set up your partition scheme, leaving the disk format as HFS+ (Journaled). You may need to resize the Disk Utility window, as I couldn't slide it to less than 50GB, but I only wanted 30GB for Windows. Windows will eventually reside on the last (bottom) partition, which I named BOOTCAMP, just in case that might be required voodoo later.
- Now go to the Erase tab, and erase your Windows partition, formatting this as MS-DOS/FAT32.
- You can now install Leopard, ideally on the first (top) partition, and set that up how you like.
- When you're ready to install Windows, simply insert your Windows Install disk, and reboot holding down "C" key.
- You should then start to see the slick old-school text of the Windows installer sliding down your lovely screen.
- Eventually, you will be prompted to select a disk; your Windows partition will helpfully be the only one with FAT32 written alongside it.
- The first time around, I chose to proceed without any further formatting of the partition, but the install crashed after a few minutes, and my machine restarted in Leopard.
- The second time around, I chose the Format as FAT32 (Quick) option, and it went peachily. (The glaring visual disparity between the Leopard install process and the XP one, seen in quick succession, is quite something).
- Eventually, you will see the rolling green hills of Windows, at which point insert your Leopard Install Disc, and "setup.exe" should auto-run to install your drivers.
[robg adds: I haven't tested this one.]

