The biggest excuse I hear time and time again for not using open source geospatial tools is that they are too confusing to use. Take GDAL/OGR for example, the webpage probably scares off most users because of the lack of examples of how to use both toolsets. But the tools themselves are so easy to use this shouldn’t scare anyone off. In fact, if you’ve used ArcInfo to convert a coverage to a shapefile in your past, you have all the skills needed to use both GDAL and OGR.
That said Tom Kralidis has a great example of using OGR to convert a Microsoft Excel file to KML. GDAL/OGR is integral to so many GIS applications (even ESRI uses it) that any GIS professional should have at least a basic understanding to how it works. Look at Tom’s example, download FWTools and get cracking on using GDAL/OGR.
Fans of the Waffle House wait for open source geospatial tool users to create GeoRSS feed of store locations
Spatially Adjusted 