We recently installed Wikipedia on DVD on our network and also made a copy available on loan in our school library.
It is available on the student desktops with an start menu icon next to the other 'encyclopedias' Even though this is only a 0.5 version test release, I am impressed by how popular it has become with students.
The DVD is low on eye-candy and unnecessary graphics or movies so fast to use, great for students that have run out of Internet credit, free for them to take a copy home and I am pretty sure, you can edit the content on the local version.
http://www.wikipediaondvd.com/site.php ...
Huge download but you only need to grab one copy to share.