If you just wipe out the MBR, Linux is still there. You just need to reinstall the bootloader. I think Redhat and Mandrake have a rescue thing that will do that. With Gentoo, we boot the Gentoo CD and chroot in and reinstall it there.
Removing the MBR record does not delete Linux, just the bootloader. The partitions with the OS are still there, you just can't see them. Yup, I have done this once.
Later