Today on Twitter, Justin Bieber celebrated his one year Madison Square Garden anniversary. Beliebers sent tweets to their heart-throb, reminding him that on August 31, 2010, the Biebs' dream of performing at the esteemed NYC venue came true, and thankfully for us, and for Bieber, we can all re-live the moment with a copy of the 'Never Say Never' DVD. Also on Twitter, Adam Levine celebrated the monstrous success of 'Moves Like Jagger,' while Rebecca Black tweeted about her time in the studio, and Britney Spears re-watched the MTV VMAs tribute to her. See what your favorite stars were tweeting about today!