Just wanted to share my experience with Greenback Expat Tax Service. I had to file my taxes from 2007 - to current in addition to sorting out an issue that I had with my 2004 taxes.
I had a great experience with them and would highly recommend them. They got back to me right away, and after I uploaded all my paperwork it only took a day for them to get it all done.
It was super easy. David, the guy who did my taxes was really nice.
For whatever reason I was really overwhelmed by trying to file my taxes myself. Maybe I could have done it, but I just didn't want the hassle and worry of doing it wrong. I am in the process of applying for my husband to get a green card and I just didn't want anything to hold that up.
I wrote a blog post about it if you want to read it and please feel free to ask me any questions. Cheers
http://tatertotsandteacups.blogspot.com/2011/07/expat-taxes.html