Gaydar is also the world's biggest online gay commmunity website, linking gay users across the world in a spirit of freedom, tolerance and.... well, actually it's just a personals site. A very good one though.
Gaydar splits each participant country down into a group of regions to which users belong. Users may submit many photos, and can message, email and phone other users. When visiting other users' profiles, you leave "tracks" so they can see that you've visited, and respond accordingly. It's demographic is quite balanced, with roughly equal people from the age ranges 18-30, 30-40, 40-50, 50-60 and 60+; slightly fewer users fall in the 40-50 age bracket, for some reason.
It is quite a central part of the gay culture in the UK, where the website started some years back; often gay men will swop Gaydar profiles along with mobile numbers; the site is particularly popular among university LGBT societies.
Gaydar has become so successful and profitable that it has launched its own radio station, playing a wide range of music, mostly gay bar-style anthemic dance tunes. It broadcasts live from G-A-Y Club in Soho (Britain's biggest gay bar) on certain nights, and is easily more popular than its only credible competitor, Purple Radio.
The site's url is www.gaydar.com. A sample Gaydar profile (ie, mine!) is at http://mygaydar.com/ajwazzer.