Eric E. Anderson thinks sidebars are shit:
Spoiler Alert: Dumping a bunch of stuff into a sidebar doesn’t make you a blogger. Nor does it make your website more useful.
While Anderson shares some good ideas, I think he's being harsh.
I've toyed with the idea of redesigning this site in such a way that would eliminate the sidebar, but I don't think I will. The truth is I like the concept of a sidebar, and I think they're useful provided they're used judiciously. I removed a lot of unnecessary cruft from my sidebar awhile back, and have been very happy.