Gotta use ice somehow, since a chiller can't get the wort any cooler than the cooling water (~ 90º here in the summer). I pump my wort through a plate chiller that's hooked up to tap water. The wort exiting the plate chiller is close to ground water temps. After the plate chiller, the wort then flows through a copper coil submerged in ice water. It takes 1 pass to get below 70º, or about 15-20 mins for 11 gals.
I need to take a good pic of my setup while I'm chilling so people can get a better idea of what I do. It really does work great.