On Sunday night Bill Gates takes to the stage at the Venetian Ballroom for CES’s curtain raising keynote speech, and each year he delivers a surprise guest to play Eric to his Ernie. It is probably a long shot but I wonder if tomorrow’s star turn will be none other than Mr Inconvenient Truth Al Gore. At a CES where gadgets are starting to look a little commoditised – bet we don’t see those swathes of MP3 players, PVPs and flash camcorders of previous years - makers are having to come up with new ideas to persuade us to trade in pounds for new gadgets. And what better way to do this than with a bit of greenwash.