This image was published on the NASA Earth Observatory web site.
This bee stopped on a nearby plant to clean itself -the pumpkin pollen was driving it crazy! If you view it large you'll see why the pollen is so sticky: It's not round, but has "spikes" on it.
All Canon gear: Xti (manual mode F11, 1/200, ISO 100) + MPE-65mm macro lens. MT-24EX with home made diffusers.