Here's a really great way to extend Vista Search & Organize from the "Instant Search" box to search SharePoint: http://blogs.msdn.com/joelo/archive/2006/12/08/tips-to-enable-sharepoint-intranet-search-using-windows-desktop-search-3-0-rtw.aspx. For brevity I've copied the Vista instructions below.

What's the Instant Search Box? In case you asked; it's the text box you see in the lower left hand corner of your screen when you press the Windows key or click the Windows Start button.

When you type text in the "Instant Search" box Vista will show two options by default:

  • See all results    
  • Search the internet    

With the instructions below you can add your own option which will take the text you type and pass it as a parameter to a URL of your choice.

Instructions:

  1. Click on Start Button
  2. Type Gpedit.msc, Group Policy Editor will open (Click Allow if prompted for elevated privileges)
  3. Navigate down and expand the following Tree Nodes User Config > Administrative Templates > "Windows Components" > Instant Search
  4. Double Click Custom Instant Search Internet Search Provider
  5. Choose to Enable
  6. Enter Search My SharePoint Site
  7. NOTE: The %w will be substituted at runtime with your search text url encoded.

    Replace YOURSERVER with your SharePoint server.

  8. Click OK
  9. Close Group Policy Editor
  10. Reboot or run the following command in a command window as Administrator gpupdate /force