I have been having the students in my writing class do journal
writing in a wiki and I'm spending a fair amount of time thinking
about how to structure the writing to make the experience better.
Today, Phil pointed out 
this article
which describes how wireless access could allow people during a
presentation to challenge the speaker with up-to-the-minute
information.
We are currently talking about providing wirelessly connected laptops in class. The potential is there for the same kind opportunity to transform the experience for students, but its much harder because in many of our classes the audience is not technically inclined and is often ultimately disengaged from the content: they're less interested in the 'truth' and more interested in knowing what's going to be on the test. This technology would empower students to muddy the water, which would almost certainly improve learning, but it's not clear that all (or even many) students would want to do that. Students who view learning from a transmissionist perspective are probably invested in maintaining a class environment that values simplicity and internal consistency in order to maximize their ability to memorize content.
It has been interesting to see the range of computer savvy among the students. Many of them came into the course pretty skeptical about the extent of technical capability I was expecting -- they were particularly skeptical of the wiki. I'm not sure I won them over exactly, but most of them have managed to use the wiki and some have become quite facile. I was impressed when I looked at one of the projects, where the students had produced a beautifully formatted page with italics and linebreaks and stuff. Neat!