"As a Brit, I think you should all follow us and use the Greenwich Meridian as your standard. ;)"

http://wwp.greenwichmeantime.com/home.htm

Heh, everyone does. All time zones are known as GMT+ or GMT- as well as their local names. And the aforementioned Universal Time (known as Zulu in the military) is Greenwich Mean Time. A US Navy ship visiting Australia will have its clocks set at GMT.

"But the time zones are based on latitude..."

They're based on longitude.