I just ran across an interesting weblog. Henry Wilton taught a course in the spring on geometric group theory, which is the use of topological techniques to prove theorems in group theory. He had his students write up the lecture notes for each lecture as a separate post on the class weblog, 392C Geometric Group Theory. I’m sorry that I didn’t find this site when the course was on-going. It would have been interesting to follow along with the class in real time.