IMPORTANT: After discussing this approach with H. Peter Anvin, the conclussion that this is not a valid usage of BIOS Boot Partition has been reached. BIOS Boot Partition is only for installs where MBR is unmanaged. HPA is currently working on a scheme that will support managed mode with MBR on GPT.

The rest of this site is maintained for historical purposes (and heck, maybe you even find the code useful for something).

This website is small and straightforwarded for your comfort.

What? An MBR that can handle BIOS-based boot on GPT.
Where? Download link here.
Why? Because users might want to setup GPT labels without ressorting to that Intel messy thing known as EFI.
How? Much like with DOS partitions: BIOS loads MBR and jumps to it; MBR finds a bootable GPT partition, loads its first sector and jumps to it. What happens next depends on what was loaded ;-)
How do I set the bootable flag? Open your favourite GPT label editor and set the GUID for your partition of choice to 21686148-6449-6e6f-744e-656564454649.
Who? Written by Robert Millan (but heavily based on code from GNU GRUB).