Gardening Australia has a great fact sheet on drought tolerant plants for the Australian garden environment.  Some of the plants they recommend include:

• A wattle Acacia cognata.
• A native grass called Lomandra ‘Seascape’.
• Coastal Rosemary, Westringia fruticosa.
• Dwarf Sacred Japanese Bamboo
• Pelargonium peltatum, the ivy leafed pelargonium.

For the full fact sheet, see Gardening Australia's - Drought Tolerant Plants.