You can now buy iTunes gifts from within Facebook's gift system. iTunes gifts in Facebook are available for $10, $15, $25, or $50, and can be used to buy videos, music, apps, and more. Facebook says:
Starting today with Facebook Gifts, you can instantly gift your friends iTunes digital gifts and recommend albums, movies, games, apps, and more available on the iTunes Store.
Search for a specific song or album to recommend, or let your friend decide. iTunes digital gifts are available for $10, $15, $25, or $50.