When you need to convert American recipes to those from just about everywhere else in the world, and vice versa, it means switching between imperial and metric measurements and between farenheit and celsius. Here are some good web tools to help out:
Online Conversion converts all kinds of measurements, but covers everything you’re likely to need for recipes, including conversions between U.S. and U.K. teaspoons and tablespoons.
GourmetSleuth has a food-specific conversion tool that lets you search for specific foods (for instance, white or brown sugar), and automatically converts amounts; it also has a standard conversion guide geared toward cooking.
DGresh notes that Google will do simple conversions for you; just type something like “150 degrees celsius in fahrenheit,” or “300 grams in ounces” into its search box, and it will show you the answer (without any search results or ads).