If you set a distance, time or calorie target it gives you updates. I measure my runs in miles and it updates every half mile. It also tells you that you are at the halfway point. You can choose between a male or female voice.
If you acheive a milestone - fastest mile etc Paula Radcliffe or Lance Armstrong congratulates me
Tells you your time, distance, pace and calories burned.
Sensor and transmitter come in at £20 and there are bargains to be had on the trainers online (from £45 I'm sure I've seen). Or you could buy the little pouches/pods for attaching the transmitter to any shoe.