When Apple announced Ping at the beginning of the month as a new music-centric social network that’s part of iTunes, the first major complaint was that the service only supported music in the iTunes Music Store, and you couldn’t like or comment on music you already had in your music library – essentially making Ping only good for suggesting music people should buy, or music that you’ve already bought.
Now, with the most recent update to Ping, you can like or post about music in your iTunes Library, as long as it’s also for sale on iTunes (that doesn’t mean you have to have bought it from iTunes though!)
The new and deeper Ping is part of the latest update to iTunes 10, version 10.0.1. Give it a shot! If you want to follow me on Ping, you can find my profile here (iTunes required for link!)