Something I thought about today is the numerous sites that use gossamer for their directories. It sends traffic to sites through the jump.cgi script.
Search engine spiders can't follow that right? So in a listing like that your not increasing your link popularity at all.
Just something to think about. Whenever I use gossamer I modify it so it dosent use that jump.cgi thing and sends the traffic right to the url. I dont care about keeping track of outgoing hits etc. And this way sites can get some link pop.