Google Toolbar’s feature “AutoLink,” detects US addresses, UPS tracking numbers, International Standard Book Numbers (ISBN) and Vehicle Identification Numbers (VIN) and links to relevant pages from sites like Google Maps, Amazon or CarFax. The latest version of the Google Toolbar for IE (Google Toolbar 5) adds two new patterns: “email addresses” and “URLs”. If you click on AutoLink, Google Toolbar will transform into links all the email addresses and the web addresses from a page. You can click on the button again to highlight the content that has been detected, but a better idea is to see all the results in a drop-down.
Source:→ Google System