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Attic. I bought mine in the middle of the flicker screen trouble and was worried I would have to ship it back. The box is still in the attic.
 
Basically the replies above. I had to bring my iMac into my department's IT office to install some software, and I'm glad I had it because I had to carry it a few blocks and I'd be afraid of what could have happened along the way like some horrible drop. It'll be extremely useful when a new iMac comes out and you want to sell.
 
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