My answer:
A bunch of receipts; $4 in cash; some hair ties; two credit cards; a debit card; my driver's license; my membership cards for the American Museum of Natural History, the Klingon Language Institute, Kenshikai Karate, the Wildlife Conservation Society, the Science Fiction & Fantasy Writers of America, FYE, Enterprise Rent-a-Car, Borders, and Barnes & Noble; my social security card; my library card; my Rarotonga driver's license that permitted me to drive a scooter; my registration card from a gun range I went to in 2004; my CVS and Stop'n'Shop cards; and my insurance cards.