I don't know if I mentioned it before, but Wolfram Alpha can also be used for travel research.
- Converting the time to other time zones
- Calculating visa dates (be sure to check whether it's inclusive of the last day or not -- I just use it for rough calculations)
- Finding distances
- Converting distances, measurements, and temperatures
There are also toolbars for Firefox, Chrome, and Safari.
Here are some more examples of what the site can do:
EDIT: I just found this page with more examples about how to use Wolfram Alpha for travel.