This one from designer Nuno Teixeira is certainly more attention grabbing than most, even if it isn't any more realistic. Dubbed the "iMac iView," the main distinguishing feature here is obviously the curved screen, which isn't actually all that far out there, but still a ways from becoming anywhere near commonplace. As if that wasn't enough, the concept also boasts a second screen on the rear, and webcams on both the front and back.

 

Source: http://www.engadget.com/2008/02/29/curved-imac-concept-bends-beyond-the-realm-of-plausibility/

Source: http://www.yankodesign.com/index.php/2008/02/29/curved-imac-has-your-back/