iRunner is a powerful application that delivers you the accurate and up-to-date statistics about your work out.
Using GPS feature in iPhone it gives you the info about the distance you have run, your current, average and max speed.
Of course the time is measured with accuracy to miliseconds. Everything is displayed using large fonts on your iPhone screen. You can also press the "Voice over" button, and they will be read for you.
Voice over doesnt stop the iPod playback.
Units can be displayed in imperial and metric units.