I read about someone who only accepts plain text mail (filters them out) and gets basically no spam.

I think disposable e-mail addresses are the way to go. I use Mailshell and Spamgourmet. Both of which are free, despite the literature on the Mailshell website, though I did end up buying a year to get the extra MB once I filled up my 10mb box... I don't know what I'll do in another 4 years.

There's also a service, I forget what it's called, but it's a plugin for Outlook, and it connects to a database of other users... If enough people delete certain e-mail that everyone else has, yours automatically gets deleted too. From what I hear it's pretty reliable, and doesn't have too many false alarms, but I don't trust it... Oh yeah, and I don't use outlook.