I doubt I'm a Luddite either (after all here I am indefatigably Web 2.0ed!) - but I do wonder about fashions of thought (disturbed since I read my first (unreferenced) article about 'digital natives', now 'multitasking')
On the other hand (isn't there always!) it's so easy to select appropriate readings for our own particular 'thought enclave'. A superb current exploration of this is in True Enough by Farhad Manjoo.
Jill, I'm not trying to be contrary--I agree with you--we need to pay attention to how we teach and how our students learn. My concerns is many teachers think kids are uber-tech savvy. I contend that many of the skills they have are low level skills--txting, uploading videos, downloading music etc. I don't think those skills need to be fostered in the classroom. I want my students to work with high level skills--analysis, synthesis, evaluation etc. If the Web 2.0 skills help kids do that then fine--but the tool is not the 'thing'.
John Medina discusses this in Brain Matters. This book is a great resource for teachers. The author makes a point to explain how brain research applies to various aspects of schools and education. You can learn more here: http://www.brainrules.net/attention
I think this could be a very powerful tool if used appropriately and in the right context. It could be used as a version of "think-pair-share" with the added advantage of students being able to see all their classmates thoughts and reflections...not just their pair! The teacher could tell the students up front that they are going to go over new information for five minutes and then they are going to have time (maybe 3-5min) to reflect on that information by updating to twitter and then responding to others comments. It is also a great way for teachers to get inside the minds of their students and see what is really going on...how much of what I just covered do they really understand? I think it would be very eye opening as a teacher to be able to read back through my students comments and discussions after class to see what was really going on inside their heads! Could be a great "ticket out the door" activity at the end of class too!