I like archive.org. I've mirrored thousands and thousands of their math/science ebooks into my apocalypse drive right next to the copy of wikipedia/wiktionary/wikispecies/etc and every binary/src package for the two distros I enjoy the most.
I've often thought of what humanity would due given an apocalyptic scenario, and individually what I would do. I've never thought about creating an apocalypse drive, but am now considering making one! I'd be curious to see/ compare peoples full apocalypse drive.
In theory I'm sitting on most of humanities basic hard knowledge and every significant piece of Linux source code. If for example a solar flare took down the grid for a couple years I could help setup local communication networks with solar and low power computers with long range wifi with web/ftp/irc/etc servers pretty easily.