Mac only: If you're a fan of OS X's Automator application, then you'll love new web browser Fake. It has its own workflow creator in the sidebar, allowing you to automate repetitive tasks right from your browser window.
Self-described as a mix of Safari and Automator (and accurately so), this browser from the creator of Fluid is pretty useful for those that need to automate browser tasks, like web app developers. However, you can also use it for simpler, everyday stuff, like filling out lengthy forms, getting screenshots or pretty much anything else you can think of. Since it's powered by AppleScript, you can make your workflow do anything you want, as long as you know how to script it.
Of course, you don't have to know AppleScript to make use of Fake. Just like Automator, it has a library of drag-and-drop actions that can take you pretty far. You can even save and reload workflows for later use. The app is currently in early stages (it's being released as time-limited demos while it's still in development), so there are probably quite a few more features to come, too. Hit the link to check it out.
Fake is a free download for Mac OS X.