For those of you who would like to add a little more bite to your strat, let me tell you how I made a simple modification.
I hardly ever use the bridge pickup because it sounds a little too dirty for my taste. So I picked up a Seymour Duncan little 59'er mini-humbucker. These pickups will fit in the single coil slot on your strat without changing or modifying the pickguard and faceplate.
You have to unscrew the faceplate and slide it off under the strings. I accomplished this without removing the strings by loosening all but the low E string and it came off easy.
Next you have to desolder and remove the single coil and then solder the mini-humbucker in while following the wiring diagram that Seymour Duncan includes with the kit. Put the faceplate back on and retune your strings and you're all set.
This mod has given my favorite guitar much more versatility and I don't have to switch guitars anymore for certain songs. Of course you can buy a strat with a humbucker but for those of you who have an original this is cheaper than buying another one.
Check out some reviews of these pickups here: