How can I chill ice coffee quickly?
Brew it strong and then add ice. Alternately, freeze some coffee in ice cube trays and use those frozen coffee cubes to chill the new batch without diluting it.

Agitation (shaking) with cubes is a good substitute for crushed ice -- both ensure that the hot coffee meets the cold surface of the ice quickly.

If you sweeten your iced coffee, using chilled simple syrup will help cool the brew and avoid problems getting the sugar to dissolve (sugar doesn't dissolve well in cold liquids).