You know what would make a good app? Take a basic database program, allow the ability to add/update entries, and tag everything you modify. Have a web site which tracks databases for different subjects (IE: drug references, computer info, how to make mixed drinks, whatever...). When your Z gets an internet connection, have the program submit your updates to the website, for approval by whoever admins that particular database, and download all new entries so your file is up to date. With some community assistance, we could come up with some good pocket references in no time.
A couple of notes (in case someone tries to write this). Any entries made by the user need to be kept in a seperate field, to be displayed alongside the \'official\' existing notes. These will be retained there until such time as the user\'s comments get added to the official reference. (After all, if someone makes their own notes and they\'re not accepted for public use, that user will of course still want their own notes available).
Yep, I gotta learn how to write code on the Z one of these days...