Just tested a great tool to multiboot almost any OS. It's called EasyBCD it's free and very easy to use.
EasyBCD 1.51 supports booting into Windows Vista/Longhorn Server natively; Legacy versions of Windows via NTLDR; chainloading into GRUB, Darwin, Lilo, FreeBSD Loader; and natively booting into Linux, Mac OS X, BSD, ReactOS, SkyOS, and many more.
Good isn't it? I love EasyBCD, Use it to dual-boot FC6 and Vista.
If you like it you really should donate, the author's a great guy.