Configuring the AddThis module for Drupal
It wasn't immediately obvious to me how to configure the AddThis module's toolbox feature using the AddThis Drupal module. The toolbox is the set of larger icons rather than the pill shaped "share" button.
After installing AddThis, go to Site configuration > AddThis > Configure (admin/settings/addthis/config). Under Widget type, select Toolbox.
If you now viewed one of your nodes that should display AddThis or the AddThis block you will see that there are no buttons. This is because they must be set under AddThis global configuration settings, Toolbox services. In this textarea you need to enter a comma separated list of buttons that you wish to appear.
facebook, twitter, linkedin, email, delicious, compact
Will show the Facebook, Twitter, LinkedIn, Email, Delicious icons as well as the AddThis button (orange with a white plus) which will be default show a popup of all the other services.
The rest of the AddThis settings are fairly self explanitory at least on the initial Configure tab.