Finally, I found the right gadget! I can start adding buttons to some of my favourite blogs or programs I'm following - for those who need to know, you use the "ADD HTML" gadget and copy/paste the code from the blog you want to feature! Now to go back and find them.
**Edited to add: I was too quick on the draw. I haven't quite figured where to find the code for those who don't have the little code box underneath. When I figure that out, I'll share it as well.