These USB flash drives are designed to look like old robots. Each holds up to 1GB of data and to access the USB connector you simply remove the robots head.
They each measure 3.5 inches x 1 inch by 0.5 inches and are available in several colours.
The robot flash drives are compatible with both Windows and Mac OS X and have keychains allowing you to easily carry them around. They each cost $18 from LazyBone.