I have one public usenet account and one public email account (used for business purposes so put onto every form, application etc I ever complete). I'm getting around 10-20 spam a day on the email one now, which I'm still manually deleting. The usenet one was up to 300 a day though, so I actually got around to configuring spamassassin last weekend.

I suspect, though, that rather being an indicator that more addresses are harvested from usenet, it's more that this address has been around so long it's on every spam list ever derived from usenet ever.

There was an interesting slashdot yesterday about how we should dilute the success rate of spam by sending genuine sounding, but actually false, replies to it. I can't find it today though, although I wanted to for another thread on a mailing list (synchronicity rules).