In case you've missed this, Cow&Gate are sponsoring some programmes on C4 (in particular, Supernanny) so there are these bookends before and after the ad break featuring a small child trying to eat his or her toys and other household objects. It's quite humorous really, but sometimes you have to actually think about what you are saying.
Another one I seem to remember is "more iron than a set of keys", which is only true because the keys in question happen to be made of plastic.