Rated 4 out of 5 stars
Its a handy tool especially while posting on twitter. I always do a double work getting the url shortened from a site and post, or completely on echofon or other tools to expect them to shorten it. Now I can independently post on twitter with URL shortened :)
am using ff4 beta, so only now I could test it, works great :)
waiting for the other enhancements listed !!