That area is not customizable, but here are some options for customizing the rest of your Start menu.
You could check this thread for some workarounds, though.
Cheers,
Walker
Windows Outreach Team
My Computer
At a glance
Windows 7 Home Premium (64-bit) *** Windows X...AMD Athlon Neo X2 1.6GHz *** Intel Core i7 Qu...4.00 GB *** 4.00 GBATI Radeon HD 3200, 384MB *** ATI Radeon HD 4...
Computer Manufacturer/Model Number
HP Pavilion dm3 (netbook) *** 27" iMac (Dual-Boot)
OS
Windows 7 Home Premium (64-bit) *** Windows XP SP3 (32-bit), OSX 10.6
If you would like to move the Windows Explorer icon (the one that opens your library) to the bottom right of your taskbar: right-click the taskbar and deselect "Lock the taskbar". A dotted line will appear (see image) between the start button and the Windows Explorer icon. Click on that dotted line and drag it to the right side.
If you want to add a shortcut for a different folder you have to make a custom toolbar.
Visit this link if you are interested in setting one up.