I really like the Windows 7 Taskbar and in particular the jump lists to have access of my documents/folders that I frequently use. Adding a program link in the taskbar is extremely easy but there is not an easy way to create a quick link to a particular folder.
For example, I wanted a taskbar link to my Download folder:
In the following page, you can find a useful tip to solve this problem:
http://www.unawave.de/windows-7-tipps/folder-to-taskbar.html?lang=EN