In New York City (where I used to live) bicycle messengers would often roll up one pant leg so as not to get it caught in the chain/sprockets. Pretty soon it became fashionable to walk around town with one pant leg rolled up to the knee and the other normal.

Ridiculous how these things come about, isn't it?

Over on the West Coast, certain gangs had one pantleg rolled up as well.

Frickin' goofs!

Again, it's to emulate what they see on TV and be a wanna be gangsta. I don't think "real" gangs do this anymore but when they did which pant leg you had up determined which side you were on, kind of like red vs. blue bandanas. Every time I see this stuff on a kid who lives up in Summerlin (our rich part of town) I wish someone would pick the kid up in a van (say a white chevy express install van) and dump him off in the real hood. See how long it takes for him to dial up mommy on his new iPhone.

Hi Five! Stanley. I've been tempted to do that to complete strangers!!! It is funny to watch them try to cross a busy street without dropping their drawers though.