If you are interested in instructional technology, webtools or education you might want to start following his blog. I find his ideas to be really interesting and provocative. I like his sessions because even when he is presenting on a subject I think I already know about like RSS, he still manages to bring something new to the subject.
I attended three of his sessions, and the last on Network Literacy was perhaps my favorite. I think he described it as "a thinking session for personal learning networks." There were several ideas I'll take from the session, but here were a few of the best: the need for us to teach kids and model how to build networks in safe, effective and ethical ways; teaching kids to become "clickable"; and if you are in education, and you don't feel pushed, then you are not paying attention.
It was time well spent.