“I have made some of the best friends of my life at Apple, and I thank you all for the many years of being able to work alongside you.” — Steve Jobs (Apple)

* Steve Jobs officially resigned as Apple (AAPL) CEO with a short, poignant resignation letter requesting he stay on as Chairman of the Board. Jobs also strongly recommended COO Tim Cook replace him as per the company’s succession plan. Check out CNNMoney and Fortune’s coverage of Jobs’s work, from his design contributions to his enduring legacy. Also, for a peek at what lies ahead for Apple under new leadership, check out colleague Adam Lashinsky’s profile of Cook, updated in 2008.

* Jobs’s departure hit some people, particularly those in tech, particularly hard. For some choice reading, also look to Walt Mossberg’s essay on All Things D on how yesterday marked the end of an “extraordinary era,” The Wall Street Journal’s round-up of Jobs’s best quotes, or GigaOm’s personal tribute. (All Things D, The Wall Street Journal, GigaOm)

* Facebook reportedly plans to add photo filters to its mobile app some time over the next few months in hopes of capitalizing upon the success of the popular photo-sharing app Instagram. (The New York Times)

* Meet BBM Music, Research in Motion’s (RIMM) BlackBerry Messenger add-on music service that will run users $4.99 a month for the ability to stream and locally store up to 50 songs. (That’s not a typo.) The company hopes by implementing this cap, users will be encouraged to connect with other BBM Music users’ libraries. (This is my next)

Don’t miss the latest tech news. Sign up now to get Today in Tech emailed to you each and every morning.