A More Proactive Approach
A while back I had two phone lines, and replied to spams, giving spammers my second phone line number. I let the computer answer the phone. Of course, you may or may not be dealing with the spammer himself, but you are dealing with the end user of the information. If enough people poisoned the well like this, they wouldn't be so keen to use spam as a way to harvest names.
Naturally, this is never gonna happen, so you can do it just for fun.