I have a small non-profit client that occasionally (once or twice a year)
needs to produce charts for inclusion in PowerPoint in the form of the US
map, with states colored based on the data in the spreadsheet. These are
extremely small sheets, and so infrequently produced they don't need the bulk
of the features, and can't justify the $300 cost of MapPoint.

Are there any free, open source apps out there that can simply generate the
US map with state colors and legends from data in Excel 2003/2007 sheets?