Choose a thread, 10th or 20thj thread in Foo, and tag the originatior, and he's it, and has to tag either the 10th or 20th thread OP. If this issues their own thread that 's 10th and/or 20th, then they add one more. If that doesn't work, they apparently post too much on the internet!
The stickie threads aren't part of the count, by the way.
@jsharr : Tag, you're it!