HSTracker provides direct links to a few useful Apple related sites that publish technical information about Apple products. If you entered your Apple product serial number into the appropriate field in the Hardware Detail window, you can use the Apple Specs and AppleCare buttons to link directly to a page about that particular model on the Apple support site.
Apart from finding the warranty status of your computers, the AppleCare serial number lookup also serves as a useful way to find the exact model name for a computer.
Knowing the exact model name, such as "iMac 24-inch Early 2009" is useful when looking up specific information about the computer. It's also used by HSTracker to call up the excellent free utility Mactracker, a technical Apple product catalogue.
Even more options are available from the Utilities menu.