You can find other cribbage players through local cribbage clubs and recreation centers, and you can play virtual cribbage online. Many different websites such as Pogo and Yahoo! Cribbage offer cribbage games for free.
The American Cribbage Congress is a good place to start looking for a local cribbage club, as they maintain a map and directory of 185 clubs across the country.
Some online cribbage sites allow players to play against each other, while other sites only provide a computer opponent. In addition to Pogo and Yahoo!, some other cribbage gaming sites include eCribbage and GameColony, both of which also host tournaments.