I am working on my first project involving a vendor in the UK. Now I've been used to working with folks west of me and adding/subtracting 1-3 hours when planning meeting times. But I was just getting fed up with anything over 3. So I found this. A Microsoft app that shows a popup of current time in whatever time zone you desire!
Check out the screenshot. The only downside is my system tray is overflowing now.