The time is right to support Madonna on the US charts and get her back to the top of the Billboard Hot 100. After only one week 4 Minutes debuted at a stunning #23 on the Mediabase Pop Chart with 2.500 plays.
But this week is even more important as the new single is finally available as a digital download. Here are the links where you can purchase and download the song by now:

iTunes links:
Buy '4 Minutes' single ($0.99)

Pre-order 'Hard Candy' standard edition (includes bonus track 'Ring My Bell') ($11.99)
Pre-order 'Hard Candy' deluxe edition (includes three remixes and 'Ring My Bell') ($13.99)

Alternative links:
Real.com MusicStore
Amazon.com
Walmart.com