Ok, I've started running, so it's only fair that I should be allowed to buy myself a toy isn't it?
I've bought myself a Garmin Forerunner 305 watch thingy-ma-jiggy which comes with GPS, heart-rate monitor, training sessions, bicycle modes, you name it. Much to my dad's delight I still have not found the feature for telling the time! Anyway, it's not a watch and who cares what time it is when you're dying on a hill.
I am pretty happy with the 305. It's a chunky monkey but pretty light and you don't notice it there when you're running.