Since Aug. 1997 I've been collecting all the spam that hits my inbox. In the beginning it was adverts for golf clubs and green card lotteries. Of late, much of the unwanted junk I've received has been Windows worms, spammy replies from "virus" filtering companies, all mixed in with the usual frauds, scams, penis pills and so on.
I used to make all this stuff available online, but unfortunately far too many people decided they wanted to download it using rude Windows-based "download assistants" which subvert TCP and kill my DSL connection. I've stopped making it available, and instead I'll put up some statistics and highlights.
As of now (Aug. 2007), I've collected 6.7 GB of unwanted junk in around 810,000 messages.
The spam archive is currently not online, but there is an old version (1997-2004) over at the Internet Archive.
I was interviewed for Radio 4 about the spam archive here.
(because, collecting all your spam is apparently not that unusual ...)
Paul Wouters has another spam archive at http://www.xtdnet.nl/paul/spam/.
Another spam archive (Japanese) at http://www.spams.f2s.com/index.html.
The spam archive was used to generate rules for SpamAssassin.
Bruce Guenter has put up his spam archive at http://www.em.ca/~bruceg/spam/.
Tels has a spam archive with nice statistics: http://bloodgate.com/spams/.
Paul Graham has been doing to nice stuff with Bayesian filters to get rid of spam for a web-based spam-proof mail reader. See his web page here: http://www.paulgraham.com/spam.html
Someone, possibly called Ogo-chan, has some more spam information here (in Japanese): http://www.nurs.or.jp/%7Eogochan/spam/