Working on the news channels template, I needed to choose again a "share" button. I was using gigya button and I knew it's ok, but I was happy to see that they have improved some things.
First, it looks better.
Second, and much more important, testing it with twitter, I see that they shortining the url for us on the fly. Nice of them.

It's very easy to implement.

http://www.gigya.com/site/partners/api.aspx