I started using Flickr a while ago, and I've just upgraded to a pro account. I've not yet completely got it integrated into my photography workflow, but I'm getting there.
Some tools that certainly looked interesting.
Multiple Uploads from a watched directory. Perhaps I could now just set this to watch the portfolio directory that I have, and it would keep Flick updated
Picasa is a great local browser of images, but only set to go to Google's own blog. Being able to blog from Picasa to Flickr looks attractive
Finally a very nicle way of showing Flickr hosted pictures on your own site!