Find Friends on Flickr
However, one area where Flickr falls really short is finding your friends. Sure, if you have a GMail or Yahoo! Mail account you can find people via that, but what about everyone else? Enter Flickr Friends!
Flickr Friends is a great little site that will take an address book export (including a vCard dump from Leopard’s Address Book) and find anyone in your address book that has a Flickr account. It’s great stuff and I was able to connect with a bunch of friends right away.