Yeah, I think it is a good idea. Some people might be reluctant, especially if they are already on your blogroll, but it is so much more easily visible- right there in print. Not everyone will take the time to go through your blogroll unfortunately. Especially if, like on my blog, you have to click a link to get to it. But the TopSpots widget is right there on the front page.
I figure it is super cheap blog advertising.
Anyway, I put it on there. We'll see how it goes.
Scratchback is a great idea I think. I have one, but took it down. I might put it back up and give it a go.