Over the past few years I have spoken from time to time about Customer Relationship Management (CRM) packages and how companies such as Hub Online (owned by realestate.com.au) and others are integrating these packages into their property management systems.
I have always though one day a company would build a CRM web based solution specifically for the real estate industry. The first to do so (as far as I know) as a standalone product is RealFutureCRM
RealFutureCRM at the moment it is specifically targeted at US agents, but really it would not take too much effort to customise it fro an Australian market. Take a tour of their software. It does look basic but it also looks to have a great feature set and at $299 USD per annum for the top level package it is also great value. That is of course if it does all it says it can do!