Yeah, I can still boot into the OSes (I didn't defrag my Vista partition, though).
If fdisk can't read the partition table from any of the OS, You are in deep doo doo. Do you have a copy of your partition table anywhere? I've got copies of mine all over the internet, and this forum particularly. I've even sent copies to myself as email, so I can do a recovery from almost anywhere.
If you have a copy that shows the start and end cylinders of each partition, recovery is a matter of a few minutes. If not, I would be copying off, to another drive, everything I could get off this one.