If you’re using Win8 yet, no doubt you’ve run into the charms bar.  There’s a feature to extend via Share, links to your application.

Details on the HOW are here:

Adding share (Metro style apps using JavaScript and HTML)

http://msdn.microsoft.com/en-us/library/windows/apps/hh758314.aspx

Do, Digital Folio has taken their shopping tool to Win8 and enabled some really cool ways to take advantage.  I was fortunate enough to help out the folks there a while back on some other things, but their app is a nice shoppers aid.

Digital Folio for Windows 8 | Instant Price Comparisons from Major Retailers on the Products You Want