Measurements & Temperatures
Use the Sneaky Kitchen's metric and U.S. calculator to quickly convert recipes.
Global Gourmet has conversion tables with built-in calculators: U.S. to metric by volume, by weight or by length; U.S. measurement equivalents and U.S./British oven temperatures
Found in Tip du Jour's great newsletter: There are a lot of conversion sites on the internet but Online Conversion has conversions for everything imaginable: Cooking, Angles, Light, Length/Distance, Clothing (convert sizes from different countries) Volume, etc. It's sort of a one-stop for all conversions!
Pioneer Thinking has a handy online conversion table for both Imperial and Metric Measurements as well as a Common Equivalents Chart from the USDA Nutrient Data Laboratory.