Other people collect signature quotes as well.
A number of quotes come from cartoon strips. Some of these are Calvin & Hobbes and Dilbert.
Some people use quotes from various comedians like Dave Barry and Steven Wright.
Politics and politions are always a source for quotable material. Some polititions say enough all by themselves to warrant a separate section like Dan Quayle (who makes it almost too easy), and George Bush. All of the rest have been gathered into a catch all file of political quotes.
This is a computer network, and many of the quotes are about computers. Some are from particular people who tend to get quoted like Henry Spencer and Larry Wall (of Perl fame).
Some topics just get beat to death, like Signature Virus.
Some companies and operating systems have their own categories, like Micro$oft, Linux, and Unix. Note that lots of people have things to say about MicroSoft, you might want to take a look at:
People tend to talk about religion, both for and against. Some of those discussions get quoted. Some are quotes.
Technology shows up in a variety of places besides computers. There are snippets about aviation and general science.
Not all is in a serious vein and some is about science fiction and Star Trek. There is a collection of Babylon 5 quotes maintained by email@example.com.
Finally, much material refuses to be pigeon holed, so ends up in a pile at the end here.