I’m traveling this week to the hinterlands of Arizona for some marketing so posting will be very light, but Paul is filling in very nicely with some of the points that needed to be addressed from the discussion last week. He’s got a great point about skills already existing for using open source software:

• PostGIS: Already worked with Oracle Spatial or ArcSDE’s “new” spatial SQL feature? You already know PostGIS.
• Mapserver: Learn the .map file and you are good to go. No harder than picking up enough AXL to be useful. Budget a couple days of learning time.
• OpenLayers: Already worked with Google Maps? You’ve got the concepts down pat. You’d better know Javascript, but that’s a transferable skill and you’ll need that for any non-trivial application.
• Geoserver: Point and click through the interface. Do you known enough to deploy a WAR into production? If you installed ArcIMS, you already do.

Sean is spot on with is analysis as well.