A friend of mine edited the html on her blog so that she could have 3 columns, and I rather liked it! So I did the same thing.
I have often wanted to make my list of things on my side bar shorter so that it wasn't so far to the bottom of the page. Mission accomplished!
If you want to do the same thing, check out this tutorial. It is a little confusing, and if you've never edited html before you might want to ask someone to help you with it. Or just be sure that you save the existing html before you go tweaking your blog.