M.D. Creekmore at TheSurvivalistBlog.net posted about an app that someone created which would allow you to Take Wikipedia Offline and “have the world’s knowledge at your fingertips.” Though I haven’t tried it (and it does cost money) you can use this app with your iPhone, iPad, and iPod. Since I’m considering an iPad (or other tablet) for my emergency preps, this app might come in handy too.
I’m the creator of this app — thanks for posting. I’d be happy to answer any questions that you have.
Evan