AirDrop allows you to share files with other computers which also have AirDrop installed using Wi-Fi (uses ad-hoc if not connected) or wired network.
AirDrop only is active and shares files when you have the option selected in the Finder window and will stop sharing as soon as you deselect it or close the Finder windows.
As you can see from the image the AirDrop Icon will change and give you visual feedback if it is running or not. The active icon is animated with a circular sweeping motion which reminds me of a sonar display.
AirDrop can be considered a security risk and can be completely disabled. If you wish to disable (or enable) open the Terminal Application (located under Applications/Utilities) and type in the following commands.
defaults write com.apple.NetworkBrowser DisableAirDrop -boolean YES
defaults write com.apple.NetworkBrowser DisableAirDrop -boolean NO
You will need to Restart, Log out and back in or relaunch the Finder from the Force Quit application (from the Apple menu or Opt+Cmd+Esc). Once disabled the option will be removed from the Finder side bar.
Just upgraded to OS X Lion and right after the initial boot all of my icons on my desktop were gone and I wasn’t able to right-click (option+click).
I tried removing my com.apple.desktop.plist and com.apple.finder.plist form ~\Library\Preferences as well as ~\Library\caches with no luck.
Finally, opening the Terminal app and running defaults write com.apple.finder CreateDesktop -bool true and Relaunching Finder from the Force Quit menu (under the apple logo in the menu bar) restored my desktop.
If you’re having the same issue, I’m not sure if removing the plist files from my Preferences folder helped, but I would try running the defaults command first to see if it solves your problem.