Use a Different Wallpaper on Each Desktop in Vista or XP

DisplayFusion - http://www.binaryfortress.com/displayfusion/

Place a fully functional Microsoft Outlook Calendar on your Desktop

OutlookDesktop - http://www.michaelscrivo.com/projects/outlookdesktop/

Create a taskBar for the extended monitors and add additional functionality to Windows with multimonitor support

Oscar's Multi-Monitor TaskBar - http://www.mediachance.com/free/multimon.htm