i think this is a feature in the yahoo toolbar (believe that you have to enable it through there.) however you may want to make sure that you want this, it has a sketchy reputation, although there are legitimate uses
The information on Computing.Net is the opinions of its users. Such
opinions may not be accurate and they are to be used at your own risk.
Computing.Net cannot verify the validity of the statements made on this
site. Computing.Net and Purch hereby disclaim all responsibility
and liability for the content of Computing.Net and its accuracy.
PLEASE READ THE FULL DISCLAIMER AND LEGAL TERMS BY