The English version of Wikipedia is about 650,000 articles, which comes out to about 1 Gig compressed database — that easily fits on a PDA / cellphone these days. I’ve been thinking for a while now that I should look into loading it all onto my Treo 600, but I see now someone has done all the work for me!
Erik Zachte has produced conversion scripts as well as detailed instructions on how to convert the complete Wikipedia Encyclopedia into TomeRaider ebook-reader format for Pocket PC Windows and Palm OS. Text-only version fits in just over half a gig, text + images is 1-2 gig depending on image down-sampling. I also like his “Build, Buy or Borrow” plan: you can use his scripts to build your own latest version for free, buy the latest version on CD or DVD, or download for free his semi-anually updated version direct from the Wikipedia server. That’s exactly the sort of “free as in freedom” software business plan I hope winds up succeeding in the new economy.