In July 2011 Google Scholar introduced with Google Scholar Citations a simple way for authors to compute their citation metrics and track them over time. This service has now been made available to everyone.
Google Scholar Citations allows you to create a public profile that can appear when someone searches for your name. Furthermore it enables you to follow your and your colleagues' citation metrics. More information on the new release can be found on the Google Scholar blog, or sign in and follow the instructions to get started.