Every Time Zone is a great way to track the time zones across the world quickly and easily. What makes it especially cool is the fact that you can move a slider along the time line to check different times in world regions before they happen, which is very useful for arranging conference call timings with foreign locations.
It also sports one of the easiest interfaces I’ve ever seen for identifying dateline changes. If you’ve ever had to call Australia from the Europe and struggled to remember which day it was, let alone what the time was over there, then this is the site to bookmark. You can see instantly where your colleague in Perth is on the temporal continuum. It’s brilliant. Now if only they would convert this to a nice smartphone app.