Good old gaydar. Even if it is just a glorified virtual cruising ground, it's still the easiest way to chat to guys from all over the world - or just secretly look at their pics and read what they say they like doing in the sack. Always busy (if it's early morning your time, head for the chatrooms or profile lists from countries on the other side of the world), gaydar's interface is straightforward and practical. The limitations on free memberships can become a little restrictive, but occasional or casual users will probably get their fill without ever paying a cent.
Also a sponsor of real-time events like the Sydney Mardi Gras, Gaydar is probably the most comprehensive, and most used, gay meet and chat site on the internet.