VESA-mount gives iMac wall-mounting abilities, adds $40 to the price tag
http://www.notebookcheck.net/Apple-adds-VESA-mount-option-to-iMacs.89844.0.html
This concept was launched originally in the year 1997 and it was called FPMMPMi or Flat Panel Monitor Physical Mounting Interface. Later, it was shortened to FDMI or Flat Display Mounting Interface. Screws are mostly included in VESA wall mounting hardware but they are also sold at hardware stores.http://www.whatisall.com/technology/what-is-a-vesa-wall-mount.html