A campaign I am in had a magic library of black stone obelisk-books each an immovable and apparantly indestructable. '1x3x9' slab, arrayed circularly around the indexing device. Words, unreadable to us, would fly accross the surface upon command...by an NPC. This lost treasure was protected by a large (4 squares) mechanical cat, armed with laser cannons and a bad temper against anything which tried to scratch the obelisks....sorta like Digital Rights Management there.