Here are some Links of Web Sites which have Online Conversion Utilities
CALCULATOR.ORG - Online Conversions & Constants
Digital Dutch - WWW Unit Converter
Google.com Directory of Online Converters
Institute of Chemistry, Berlin - Conversion of Units
TAMI Industries, France Area, Cost, Distance, Energy & Power, Flow, Pressure, Speed, Temperature, Volume
Yahoo Directory of Online Converters
AllMeasures.com - Units of measure, conversion table, converter