To convert all kinds of measures:
http://www.convert-me.com/en/convert/length

To find what accronyms stand for
http://www.acronymfinder.com/

To know the time in any part of the world:
http://www.worldtimeserver.com/

To find out about the weather report in any part of the world:
http://www.worldweatherserver.com/weather_in_CAAB0001.aspx

On-line dictionaries:
http://www.dictionary.com

Currency converter
http://www.xe.com/ucc/es/