I think it would be fun being able to trace one's GMail Invite Lineage.
I got mine from Mark Baker.
Now if Mark reads this and says in his blog where he got his from and that person says on their blog (assuming they've got one) where they got theirs from...
So a call to all bloggers with GMail accounts: spread the meme!
UPDATE (2005-02-09): Mark Baker replies:
I got mine from my old friend Nelson Minar, Google employee. I expect I know where he got his. 8-) Actually, let's save a whole lotta time and just ask him for a dump of the invites database. 8-)
Wow, I'm only two steps from the source!
I did figure Google could produce the family tree themselves. Perhaps someone can work on a browser into that for their 20% project.