I'm doing a lot of that (UI testing) in my Let's Code Test-Driven JavaScript series (http://www.letscodejavascript.com, starting with episode 41). My next Lessons Learned video (#10, coming out this Friday) covers the underlying theory. There's a free trial if you want to check it out.

If you're more into Java, or then I also do a lot of test-driving of a Swing GUI in my original Let's Play TDD series (http://www.jamesshore.com/Blog/Lets-Play). It's a lot less polished than Let's Code TDJS, but it's free.