As I work in an international company I often have to contact people in different timezones, and its not always easy keeping track of what the time is where.
Especially annoying is it when you have to inform about maintenance and (because you are just a tad service minded) try to write all the local times as well as local time.
Anyhow, I got a few pointers this morning;
The quick way to get local time anywhere is;
http://www.timeticker.com/
If you are planning meetings etc;
http://www.timeanddate.com
The latter site has some useful features, meeting planner and national holiday information.