AppleInsider posted another OS X 10.8 Mountain Lion article, this time looking into the Share Sheet feature

Apple introduced AirDrop in OS X Lion, making it easy to set up a secure, configuration free file sharing session between two Macs on the same network. In Mountain Lion, Apple makes the feature accessible all over through the new Share Sheets feature.

Share Sheets present a "send" icon familiar to iOS users in a variety of places throughout OS X Mountain Lion, from Quick Look panels to Open File dialogs to Contacts, Safari and Photo Booth.

  Inside OS X 10.8 Mountain Lion: Share Sheets put AirDrop, Twitter, Vimeo sharing everywhere