Stew-Mac sells pre-wired Strat pickguards with a terminal strip soldered to the volume pot so you can install the whole rig without a soldering iron.
I use a quick disconnect similar to a molex connector inbetween the pickguard an the battery/ground/signal wires going to my jack. I can swap pickguards with different pickups and it makes disassembly a snap. I have a strat-ish guitar with EMG's which don't need a bridge ground. Eventually, I'll replace the molex connector (bulky...) with a radio control servo extension cable. Cut the extension in half, plug the ends together, and use the 20AWG leads to wire up the output, power, and ground between the pickguard and the jack. They're even color-coded... which is quaint.
As a sidenote, I use a 23A 12V garage door opener battery (like a AA, but only about half as long) which fits right inside the jackplate rout. The battery holder (an N-style holder works... get it at Radio Shark...) sits in there fine and changing batts doesn't require anything more than removing two screws...no battery box and no need to find room in the control rout. The 23A and holder will also fit inbetween the trem springs for Floyd/Fender/Wilkinson style trems, Provided, of course, you aren't using all five springs.