Hey, Drusilla/Blue Floppy...is that you? And Camilla/glamandtonic! Nice to see you here.
Yes, it is possible to add a Digg It link to the bottom of each post in Blogger! I had seen other people on Blogger with it, so I went ahead just now and figured out how to do it. (I had been putting off doing it on my own blog.)
Basically, you have to go in and change the HTML. When you go to edit your template, make sure to check off the "Expand Widget Templates" box. You'll see that you get a
whole lot more code that way. Then, copy, paste and save a backup of your HTML template into Notepad or some other word processing program. That way, if you screw up your code, you can always restore it.
Once you've copied your code into Notepad, use the "Find" function to find this line of code:
<p class='post-footer-line post-footer-line-3'>
Next, you'll want to copy the following line of code, and paste it right before the previous line of code:
<a expr:href='"http://digg.com/submit?phase=2&url=" + data

ost.url + "&title=" + data

ost.title' target='_blank'>Digg It!</a>
This is one very basic way of doing it; once you've familiarized yourself with this aspect of the code, you may want to change where you add the Digg It link. I've manipulated my own code a little more, plus I added Del.icio.us and StumbleUpon links. This is how I it looks on my own blog:
Hope this helps!