By default, Windows XP Explorer's My Computer branch and the desktop My Computer icon show folders for two document type folders: My Documents and Shared Documents. While using XP's new PowerToys TweakUI for Windows XP applet, I noticed that selecting My Computer and clearing the Files Stored on This Computer option removed the LocalUserName's Documents and Shared Documents icons from Explorer's My Computer branch and the desktop My Computer icon.
Upon further investigation, I discovered that the HKEY_LOCAL_MACHINESOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\DocFolderPaths registry subkey has another interesting use. You can modify this subkey's paths for listed local users to change the directory that the LocalUserName's Documents icon opens in Windows Explorer's My Computer branch, the desktop My Computer icon, and other File Open system dialog boxes. (These modifications don't affect the My Documents branch at the top of Windows Explorer's Folders pane or the My Documents areas of other File Open system dialog boxes. You need to pay attention to the difference between My Documents and LocalUserName's Documents.) For the string value, enter the full path of your choice; don't surround the path with quotes (e.g., C:\Cherry Hill Park). When you subsequently open Windows Explorer's My Computer branch, the desktop's My Computer icon, or other File Open system dialog boxes and click the user's LocalUserName's Documents icon, the path you specified will open. To follow my example, if you have a local user called Mary Hill and you modify her DocFolderPaths subkey, clicking the Mary Hill's Documents icon will take you to C:\Cherry Hill Park.