I thought this fit into this thread quite well...
I myself usually ride in full face, bandana, leather jacket, jeans, gloves, and under-armor leggings if it's cold.
A buddy of mine went down last year and will wear full leathers no matter what. It was 100 degrees out side and he was rocking a full pants/jacket set up.
I realize that if I go down at more then 30 mph the only thing that will matter is my jacket and helmet. I have rode BMX for 12 years and know how to crash. I know that sounds funny but, I have crashed in many of ridiculous ways, and for the most part get away with minor stuff. That however is without a 400 lbs. motorcycle chasing you and cars. I however completely realize that if I go down I will be ripped to shreds. I hope everyone else realizes that, next time they leave the house in shorts.
Also please wear long socks, when riding. Not for protection but you look retarded, with the gap between your shoes, and your pants while riding.