Iirc someone once told me that keeping the clutch disengaged over time puts pressure on the crank shaft and can damage it (cause it to bend maybe??), I think we're talking over lifetime of car. Don't know how true that is, but ever since I have put car in neutral at lights etc. Besides which it's probably safer and prevents you having one leg like Jeff Capes and the other like Mr Muscles (original obviously)
Edit. Just seen previous posts, that was it, wear on the bearin! 8)
