Start by checking twitter, #tt09. Daniel has been carpet-tweeting the entire event! Check out his coverage of Day 1 and Day 2.
Be sure to read Ethan Zuckerman posts on what Matthew Gray is doing with the Google Books data and Beth Noveck's open government keynote.
If you haven't checked out the Guardian's datablog, do it! Tons of captivating and informative information vizualization. Their talk at TT highlighted the MP Spending crowd sourcing project.
I look forward to catching up with the videos once they are posted!