This exercise is one that I originally wrote for my company's intranet. It's a password generator. Normally it loops through /usr/dict/words, but since this server doesn't provide me read access to that file (and for performance reasons on a shared server), I have used a shorter list. It provides several "levels" of strength, each a little more complex than the last.

The source for this generator can be found online, but it can be pared down significantly if you don't need all the cypher levels: pwgen.phps.