I love flickr, I think it’s a great photo hosting and sharing site. I especially like the fact that it has an open API to facilitate people writing cool plugins and utilities for it.on that note, if you use flickr, you should definitely have “betterflickr”:
http://lifehacker.com/software/lifehacker-code/upgrade-flickr-with-the-better-flickr-firefox-extension-263985.php
basically just a greasmonkey script, it provides a whole new level of functionality for flickr users (I think the most useful thing is the drop down “view all sizes” menu – awesome!)