Occasionally, you might have the need to covert, say grams to pounds or cubic meters to cubic feet. While this may not be a common situation, you most likely do not have the conversion formulas memorized. If not, a good tool to reference is webMeasure.

From the web site:

webMeasure converts the most common measurement units for you, including metric, imperial and US based values. With the menu on the left you can chose between linear, surface, volume and weight conversion. You can also chose other common sections where a conversion comes in handy once in a while, like clothing sizes.

The layout is actually very nice as you simply select the category of your conversion then enter a value in a single box and with the press of a button, all the applicable measurements are converted. Again, maybe not the most often used utlity, but when you need it now you know where to find it.