I learned quite a few useful tricks, including one that makes dealing with subversion keywords much more bearable.
If you use DrScheme, it's a must read.
If you don't use DrScheme, it might still be an entertaining read - as it's the usual: program X is nice...but it's not emacs. And here's why....
Ahh emacs, the cause of, and solution to, all life's problems. Oh wait, that's beer.