Stick pixel(s) on your new iMac? Try this self-fix tool

l33r0y

http://www.caseytech.com/how-to-fix-...or-dead-pixel/

shamingo

Or you could just call your local Apple store or simply just take it in and tell them that you called earlier and was promised a replacement (even if you weren't) and you will get it replaced no questions asked 100% of the time.