I've known that when you enter a new task in Google Calendar you can prefix it with a time to schedule it for the day. That is, I can say:
12:30pm, Write up that blog post I was thinking about
My discovery today: if I add a timezone abbreviation to the time, it'll not only add the event, but convert it to my timezone. So, I can say:
12:30pm PST, Talk with my surfer friend
This automatically gets added as an appointment at 3:30 PM my time.
Add to this the World Clock Labs option, and my Google Calendar makes coordinating with folks across multiple timezones much easier.