Ping is today's most unexpected Apple announcement. The social network will come baked into iTunes 10 and allow users to connect with friends and musicians. Apple describes the service as a music discovery program. "Follow" people to discover what they're listening to, watch their favorite music videos, find custom top-ten lists, suggest songs to others, and learn when musicians will tour in your area. Ping is free, but Apple hopes all this sharing will lead to a bunch of new 99-cent sales.