yeah and fortunately or unfortunately i am the only bloke stuck with both the 80 and 40gb versions

i've had to invent reasons on how having 2 helps!! - like watching US and other region coded blurays, etc
So on 2nd thoughts why don't you get the 40gb and then bump the hdd up to 320gb or so. Sony has no probs with you doing that and 2.5" sata hdds are available easily.