Which OS? If WinXP, you need to make a shortcut in the Quick Launch folder - or take the easy route and use quick icons -
http://www.outlook-tips.net/2004/773/tip-103-quickicons/ - quickicons will create shortcuts for all outlook item types. You can choose the item types you want and it detects the correct path if you use 64-bit windows and 32bit outlook (just tested it).
If you want to create your own shortcut (using the windows option to create shortcuts) - you'll use
“C:\
Program Files\Microsoft Office\Office14\Outlook.exe” /c ipm.note
If you use 64-bit windows and 32-bit outlook you need to adjust the path:
"C:\Program Files (x86)\Microsoft Office\Office14\Outlook.exe” /c ipm.note
But.. if you use Windows 7, you can right click on the outlook icon on the taskbar and choose from the new item types.