If you're interested in the whole area of computer security Evo then I'd recommend Secrets and Lies by Bruce Schneier. Written back in 2000 but still very relevant today.
Most people don't realise that it isn't their password itself which is saved but a Hash of it, otherwise Danny could go around logging into everyone's banking systems.
Also by focussing on the entropic complexity of a password, rather than using a random search (brute force) most passwords can and will be cracked within minutes by a tool such as l0phtcrack. Even without access to the hashcodes (which could have several possible sources) the data itself is only hashed on the serverside so sniffing the first 20 or 30 characters of each ip packet which passes across a node would probably get you enough passwords to interesting places not to need any form of cracking.
In his book he mentions some chap who set up a website of interest to sysadmins. Logon details required a reasonably complex password and company name. He had dozens of root passwords within weeks.....
