In Excel 2003, there was a feature that let you sync changes from an Excel 2003 spreadsheet to a SharePoint List and vice versa. In Excel 2007, this feature was deprecated.  I get asked about the lack of this feature all of the time.

Good news!  Back in June, we published an Excel 2007 add-in that puts this functionality back.  You can get it at: http://www.microsoft.com/downloads/details.aspx?FamilyID=25836e52-1892-4e17-ac08-5df13cfc5295&DisplayLang=en.

There's also a companion MSDN article entitled "Publishing and Synchronizing Excel 2007 Tables to SharePoint Lists": http://msdn2.microsoft.com/en-us/library/bb462636(office.11).aspx