There are plenty of strategies for finding free Wi-Fi in an unfamiliar location, but a little local knowledge often helps. The Free Wifi Wiki offers a worldwide directory of locations offering free Wi-Fi services, making it a useful bookmark for frequent travellers.
As with any wiki-style project, coverage varies depending on where you're looking. The Australian listings are a little on the thin side right now (McDonald's doesn't get its due for a start), but that's nothing a helpful Lifehacker reader (or editor) couldn't help improve pretty quickly. The Wiki uses the same MediaWiki code that powers Wikipedia, so editing it is fairly straightforward.