<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by BobbySteel:
How about the difference between a 757 and a 767? Size is hard to gauge when one is alone on the runway, and I can't figure an easy way to tell them apart...</font>
757s just look narrow, and look at the nose. The nose seems to be lower (to centre) than the 767 (that's why the 757 flight deck floor is a few steps below the main deck).