“Quick and easy access to your most recently used Microsoft Office Word 2007, Excel 2007, and PowerPoint 2007 documents. This gadget lets you easily open, pin, or unpin the most recent items from your Word, Excel, and PowerPoint MRU. Requires Office 2007.”
I am using it now and have found it to be very useful, so I can recommend checking it out. Hopefully the list of files, which currently only support Word, Excel and PowerPoint will be expanded in the future.