The link that greene posted above has a good map with the zones color coded to minimum temp ranges, and also the equivalent US zones beside the map. Very useful.
Glen (Gleni) lives near Brisbane on an island, and from a few months of discussions we've found he grows many of the same plants that I do. His climate seems to be quite similar to mine here in FL, zone 9b or 10a. I'd imagine Deb (thehazell) might be slightly cooler, being further south but similar since they are near the water, too.
Don't forget the hardiness zones are only averages of the minimum winter temperatures in a given area. They don't take into account differences in humidity, sun intensity, soil type, rainfall and other factors that make, for example a zone 8 garden in the Pacific Northwest very different from a zone 8 garden in Arizona or Florida. They are only the same zone designation because their winter lows are similar.
