Using technology in teaching

I'm interested in ways to use technology successfully and thoughtfully in teaching. New and exciting technologies are appearing seemingly on a daily basis. I am looking for ways people have found the use of technology in their classrooms, or outside their classrooms, to be effective in teaching. If you have specific examples, horror stories, things that worked great, or things that you think have great potential, please share!

Have you had particular successes with clickers? Wikipedia postings? Blogs? Electronic blackboards? Challenges with any of the above?

If you think technology is not the answer for education, I'd like to hear from you too, particularly if you have tried and true methods you'd like to share.

If you have references to particular studies showing efficacy, or lack thereof, of use of technology in the classroom (i.e. clickers, powerpoint presentations, etc.), I'm especially interested in learning more about how specific techniques have been shown to influence learning.