Internet Explorer 9 Beta (IE9) is out now and includes a featured called "Site Pinning" which is a effectively Site Specific Browsers. It's integrated nicely with Windows 7. It's easy for you as a developer or site owner to add these features to your site.
Here's the basic idea from a markup perspective from a Channel 9 example:
<meta name="application-name" content="Channel 9 Audio Player" />
<meta name="msapplication-tooltip" content="Channel 9 Podcasts" />
<meta name="msapplication-window" content="width=1024;height=768" />
<meta name="msapplication-task" content="name=Msdn Flash Podcasts;action-uri=./?topic=msdnFlash;icon-uri=Images/channel9_logo.ico" />
<meta name="msapplication-task" content="name=IE Podcasts;action-uri=./?topic=connectedShow;icon-uri=Images/channel9_logo.ico" />
<meta name="msapplication-task" content="name=Other Podcasts;action-uri=./?topic=other;icon-uri=Images/channel9_logo.ico" />
<meta name="msapplication-task" content="name=All Podcasts;action-uri=./;icon-uri=Images/channel9_logo.ico" />
<meta name="msapplication-navbutton-color" content="#FF3300" />
<meta name="msapplication-starturl" content="./" />
