Using an ad-supported website with an adblocker turned on.
Throwing away excess food
Buying books,movies, DVDs, games, etc. second-hand
Taking a tax deduction
Downloading illegal digital copies of music you own
Downloading illegal digital copies of books you own the paper versions of
Downloading illegal TV that you would have eventually got legally for free, but not for aaaaaages
Downloading a game/album/movie that you bought, but now the disc is missing/damaged
Answering poll questions when, frankly, you should be working right now.
(And as people seem to regularly be confused by this - you can change your answers by clicking on the poll link at the top after you've answered. And FB/Twitter users can answer if they log in.)
Oh, and there will be _no_ prize for the first person to start quibbling about whether downloading books that they don't own the copyright on is illegal in any given jurisdiction.