While the Worldcon was in Australia in 2010, it was Melbourne, not Sydney. It was the fourth Aussie Worldcon, and all four were in Melbourne. Another thing that we do at cons is VOLUNTEER to help run them. This past Worldcon, I was on panels, but I also helped staff the site seletion voting (for the Helsinki bid) and helped prepare for the Hugo Ceremony. Conventions are always in need of volunteers, and you may earn a tee shirt, access to the "gopher hole" or "staff den" (where there is usually more substantial food than in the con suite), or even a free membership to this year's or next year's con if you work enough hours.