During the past two weeks, students in a Trinity University seminar on hacking have been experimenting with the educational applications of collaborative web surfing. Students have been using a tool called PMOG to create "missions" related to topics such as RFID chips, social engineering, geek subcultures, anonymity, and brain hacking.
On Sunday, March 1st, PMOG changed its name to Nethernet. (Arguably, this a more catchy name.) Nethernet "lets you play, create and explore vast new layers of the Internet: lay traps, create connections between sites, and gift friends with just a click of a button! Turn your web browsing into an adventure!"
There are still a few bugs in the system, and the most interesting features are only available to higher level users, but the system definitely has potential. Check it out at: http://thenethernet.com.