Well, I use the Official Flickr app for Android and it has Facebook connectivity so that when I post a picture with the app I can upload it to my Flickr account and my Facebook account at the same time. It also has another connectivity thing, but I can’t remember if it’s Tumblr or Twitter or whatever. Another one I like is picplz. It’s got a lot of account connectivity options and let’s you upload to Flickr and Facebook as well. Plus, if you’re into adding effects to your photos, it has that option as well. Both are free. :) Edit: I use Android, but if you use an iPhone, I’m betting these apps exist for that too.