You may not need the API to do that. You can do a certain amount of
formatting with the "Digg This" button:
http://digg.com/tools/integrate
>Can anyone give me the code to get the number of diggs for a certain
>article, specified by URL? ... do I just use /stories and then specify link?
Yep.
>Is there anyway to specify a callback function?
Yep. See the Javascript Response Type: