Path Area Illustrator

for you guys who draw in Illustrator I found a helpful plugin which calculates the area of paths.
Download from here (the cs4 version works fine on my cs5)
extract the .aip-file and drop it in the plug-in folder, found in:
Library/Application Support/Adobe/Adobe Illustrator CS5/en_GB/Plug-ins

Select a path in an llustrator-file, go to Object/Filters/Patharea and there you go.