Designers can be very creative people, that’s why they are the best type of people for creative logos with hidden icons. Hidden images in icons can be happy accidents or something specifically planned with the logo in mind. Check out the first one which is one of my favorites by Ronald J. Cala II.
See above for some famous logos and try to find their hidden icons. For other logos check out Logo Lounge for an extensive library of daily submitted logos from companies and amateurs.
A logo that may not have a very hidden element is the last logo, Facebook’s places logo. Within the square there are streets that look as though they create the number 4, that could be a dig at check-in site 4square.