This is one of my favorite Share Widgets available.
There are two great sites to get this widget from, Add This and Share This. The style varies between the two. If you look in the top left of my site, you will see the one from Add This. Below, you will see the one from Share This, it's smaller. Both are great and you can completely customize them.
Working with both Add This and Share This, for the Floating Vertical Share Bar, you will have to choose Website instead of Blogger and manually add the HTML code. If you choose Blogger, the Vertical Bar disappears as an option.
If you need help with the customization, let me know.