brushed to brushless!
brushless motors are lighter and twice as powerful as brushed. lithium polymer batteries hold the most electricity to weight ratio compared to standard Nicd and Nmh. Dont believe me look at your cell phone open the battery hatch and take out battery its probably a Lithium polymer or lithium ion notice how light it is and small it is now look at the volts/ mAH pretty amazing hu? Got a laptop it probably got a lipo to.
you want to make the switch but dont know what motor, battery, ESC (ESC-electronic speed control) to get, just ask and ill give you a hand! i will need to know the motor and battery that came with the plane/ or that u are using. Are you flying glow (gas powered) and wana go electric? i can help u out their too!
Their are 2 kinds of brushless motors outrunner and inrunner whats the difference? well outrunners spin slower with more power so it acts like it has a gear box (this eliminates the need for a gear box reducing weight and noise) it also has a different design (look at pics). inrunners have a brushed appearance but their much lighter and more powerful u might need a gear box through.
update 2/20/08 new image added (not all comment boxes are working)