Geman magazine “Der Spiegel” has an interesting article on hand dryers. It quotes a study from 1998 that measured how long it takes to dry one's hands with disposable paper towels (12 seconds), reusable cotton towels (10 seconds) and warm air dryers (43 seconds). Air dryers take so long that men stop using them after 20 seconds, while women stop after 25 seconds.
The newest development in this area is called the Dyson Airblade hand dryer (YouTube video). It uses room-temperature air (=less germs) that is filtered (=even less germs). The air is projected horizontally so forcefully that it does not dry the water, but rather scrapes it off. Sounds useful to me.