Petzl Power Liquid is a great alternative to loose or balled chalk. It comprises of chalk suspended in a volatile liquid. Applying it leaves your hands with a very thin, even layer of chalk which is much more effective at absorbing moisture than dipping into a chalk bag. Liquid chalk also has the advantage of being non-airborne so does not create clouds of powder after application.
Lots of climbers like to use a base of liquid chalk at the foot of the route and then chalk up as usual if required whilst climbing.