You've probably noticed that we make extensive use of AustLii here — something that AustLii permits and encourages, in line with its open-access-to-the-law aims. Even though I've mentioned before that the automation means its legislation databases aren't always 100% correct, and so it's advisable to refer to official legislation sources for legal practice, it's still very handy to be able to link straight to material.
In addition, AustLii's free citator, combined with it's iOS App, make it a fantastic legal research tool in addition to the commercial services. (In fact, sometimes it's even better than their search engines, and something I do recommend over the traditional services.)
It costs a little under $1 million in 2011 to run Austlii, and it runs on a shoestring budget and a lot of goodwill. If you find it useful, consider contributing something to keep it freely available. Apparently contributions are tax deductible, so it might help you get something back from your tax return!