Amidst all the other Apple news from today’s “It’s Only Rock and Roll” music event is the fact that iPhone OS 3.1 (or, technically, 3.1.1) is now available. With it comes things like support for Genius Mixes, pre-cut ringtone downloads at $1.29 a pop, app organization support in iTunes 9, and Genius recommendations for apps. There’s also a bunch of polish, bug fixes, and ease of use features as well. Just connect your iPhone or iPod touch and check for an update.