I wrote an article a few months ago about the meaning of the icon “share” of Windows 8 and Windows Phone 7 :
However, things have evolved and the share icon of windows 8 has changed.
As I said, the old icon had copyright issues, Microsoft has decided to create its own icon “share” :
So I launched Illustrator to recreate the icon for windows Phone and voilà (copyright Joe Belfiore) !
So feel free to use it !
(right click and save image)