i swear one day if i get spam from anyone im gonna post their personal details.
Problem is that is something you can get done for. I find its easier to just do a reply to all on the email, explain the problem with sending out an email with addresses strung together like that and sit back happy knowing that it has gone out to everyone they sent it to.
Depending on the kind of spam you get, you can also just waste their resources, on the odd occassion I get a phone call from some telemarketing lot, i am _very_ helpful, I give them all the details they want, just happens that I am inventing the details as they ask. They spend money on phoning you, then sending you information that you requested, which you never receive and then to top it all you go on the telephone preference service so they can't call you again.
Something similar goes for Spam email, look at the original message, do an nslookup on it, if theres a domain name linked to it, go there get some contact details and set up a new hotmail account. Email them saying Im really really interested in such n such a product, they email you back, so you set up email forwardign for that account to send every email onto them, perhaps with a subject of Spam isn't nice. I did that for a little while to a couple of companies, thinks its just a coincidence but I haven't received any spam from them in a while.
The most annoying spam is without a doubt the ones that say buy such n such, but theres no link or anything similar so even if you wanted to, you couldn't buy it from them.