Britney Spears is back -- again -- with a number one song, and is giving fans a glimpse at the video for the tune '3.' On her Web site, Britney broke the news by saying: "I want to thank my fans for making "3" the # 1 song on the Billboard Hot 100 ... I am truly blessed with the greatest fans in the world and I am so happy y'all love it because I do this all for you."