I used to get a minor amount of personal satisfaction by returning pre-addressed/no-postage return envelopes that came in junk mail...stuffed with junk mail from other envelopes. Just remove any portions that bear your name/address, and enjoy a brief satisfied smile as you imagine the consternation in the receiving mail room as they open the envelope, only to find solicitations from other totally unrelated companies. It always generates at least a slight snicker and tiny uplift on an otherwise grinding day to think of the junk mailers getting pissed about receiving junk mail. It's the little things.