Forget iPhones with $600 price tags. If you want to have some fun with technology (and you use Firefox) download a great little browser extension called Wikialong. (It's free) This app is the coolest thing I've ever seen! I got so excited, I forced my fiance move from his comfortable position lying on the sofa to come take a look.
Basically, Wikialong turns the browser's sidebar into a wikipage. As you move from website to website, you can leave notes and comments. If someone else with Wikialong happens upon that page, they can read/edit/add to your comments. I kid you not! It's like Post-It notes for web pages!
The uses of this for the classroom astound me. Students working on a wiki could post a list of links for other group members to examine. At each of the links, they could leave questions, comments, suggestions for use, to which other group members respond.
Teachers could build a web-quest/ Treasure Hunt a la The DaVinci Code, with clues at each web page, which students then piece together. (Good netiquette would require you to go back and delete the comments afterwards, of course!)
Those are just two I can think of off the top of my head. If you can think of others, please post in the comments! (And, once again, thanks to Will Richardson's book for mentioning the extension.) Too cool!