We got the chance to play with Oral-B's new Triumph electric toothbrush this afternoon. The $149 brush comes with a palm-size wireless display (it uses RF technology to communicate) that provides real-time feedback as you're brushing so it lets you know how much time you've spent brushing and also what quadrant of your mouth you should be brushing.
The Triumph doesn't have any ultrasound waves like other brushes, but for all you sensitive gum types (like myself), the brush has four modes: polish, brush, clean and massage. There's even a built-in pressure sensor that keeps you from brushing too hard. The brush comes out this September for $149.