Although considered by many to be despicable (except, of course, for archy), the cockroach is in truth a miracle of nature, a veritable life-machine, the Energizer Bunny of the insect world, only without the pink floppy ears.
Cockroaches have been around, virtually unchanged, for 280 million years. They can survive ten minutes in a vacuum, levels of radiation that would kill a human in one second, prolonged submersion in water, being at ground zero of an M60 cherry bomb - though shoe heels bearing down, as well as being inside active microwave ovens, will kill them. A cockroach can live without a head for a week, after which lack of water intake will cause it to die. Not lack of head, note, but lack of water. A cockroach can go for a month without food, though only a week, as I said, without water.
Horrifyingly, a female cockroach can gain enough sperm from a single mating to reproduce over her entire life span, up to one year. I saw a documentary (on the Discovery Channel, of course) that reported that in a sealed environment, a single female cockroach that had mated just that once can have 90,000 offspring within three months. (Think about that next time you see one little baby one in your apartment!)
Although cockroaches are creepy here in North America, it's the two inch long black flying cockroaches of Asia that really gross me out. Think about it: they fly. Into your hair and everything. Now that's really yucky.
cerulean says You know, you don't have to go to Asia to encounter three inch long, flying cockroaches. They are quite common in Louisiana and Florida, at least, speaking from my own experiences. The locals call 'em "Palmetto bugs." Eeewww!
Most of this information came from the Yucky Kids World website - which you can gross yourself out at by going to yucky.kids.discovery.com - as well as the perversely interesting web site entitled "A Study of the Survivability of the Cockroach to Novel Stress Conditions", found at http://alumnus.caltech.edu/~maronj/text/roach.html
The cockroach home page at www.bio.umass.edu/biology/kunkel/cockroach has photos of some of the hundreds of different species of cockroaches, as well as a family tree. | 
