Create a keyboard shortcut to a folder or program

Select the folder or program icon that you wish to use. Create a shortcut for it by right clicking on the item and selecting 'create shortcut' from the menu.
Place your newly created shortcut on the desktop by dragging or cut/pasting. Right click the shortcut and select 'properties.'

Select the 'shortcut' tab and enter the key combination you wish to use (XP will automatically edit the combination if it is not acceptable. Just entering 'e' for example, will get you an actual key combination of ctrl + alt + e). Click 'ok.'

Now you can open the specified shortcut without altering your workflow.