Weber grills are the best.  I have an old model with the three sets of 3 holes that must be shut individually, and the ash falls into a tray underneath.  I like to save my charcoal, so these little closing devices get hot.  the Weber grill I just bought (as a gift) is the "gold" model with a single lever that can shut all of the bottom vents, plus a built in ash catcher.  A great improvement on a great product.