The version you should look for is 1.1. When you are in the Pictures Hub, you can click on an image, then click "share..." and "upload to Flickr from Yahoo!". Hope this helps!
Thanks, I got it. Unfortunately, it crashes when I try to upload a photo to Flickr from the pictures hub. That application is one of the buggiest WP7 apps I've seen, even worse than Foursquare.