Mobile sites that help you find Australian business listings.
The Australian Yellow Pages for mobile. Recently updated with a new 'browse section' for mobile relevant categories. Includes location detection for nearby results (if you're with Telstra). Maps and Directions provided for business listings.
Google Mobile (Australian local search)
Google mobile defaults to web results but you can easily select 'local' to see business listings. If Google detects your location it will display nearby results, and if not, it will ask you to specify. Local results include detailed info about many businesses, including maps, images and their web address if available.
or.. download Google Maps
Download this application to your handset (depends on compatibility). Visual map-based search interface with local content overlaid on road maps and satellite images.
Australian business listings with phone numbers and addresses. Very basic search interface, but simple to navigate and uncluttered, relevant results. You can select a checkbox for any business to request a quote (haven't tested this - got feedback?)