OK, maybe you guys living in the US don’t need any of the following resources as much or as often as I do – but I thought I’d share them.

Temperature: http://www.convert-me.com/en/convert/temperature
Money: http://www.xe.com/ucc/
Weight: http://www.onlineconversion.com/weight_common.htm (convert your weight into kilograms – it’s the quickest diet ever!)
Clothing: http://www.onlineconversion.com/clothing.htm
Distance: http://www.onlineconversion.com/length_all.htm (they differentiate between Midwestern, Eastern and Southern block)

Related but different:

World Time Zone: http://www.worldtimezone.net/
International Calling Codes: http://www.countrycallingcodes.com/