Getting the turn signals to blink faster

I've seen everything from tuned up cars to really junky bone stock cars have fast turn signal blinkers, which leads me to beleive that this is not an expensive mod. I've been told by someone, that just a little adjusment of a fuse or something is neccesary to do this. So if someone knows how to get the turnsignals to flash faster, your help would be much appreciated.