I liked Jeff's ideas of connecting more face-to-face; it doesn't always have to be an online network. (Though I'm a fairly quiet and reserved person when it comes to conferences and conventions... we'll see how that evolves over time).
I agree with everything that was mentioned in his podcast, and can see many benefits of twitter inside and outside the class, and see it as a potentially extremely valuable tool inside and outside the classroom, as more students are bringing internet-connected devices to the class (or can use school devices).