In addition to FRAPS, here is another utility that can measure the frame rates of your game. Once enabled it will open automatically with any game that is being played and will reside on the top right corner of your screen.
As it is an ATI product, there is a possibility that it will support only ATI Radeon graphic cards, but those with Nvidia cards - please check if it works for you.
The link for this download is:- http://www.guru3d.com/article/ati-tray-tools-/