Shape2Earth can get your GIS data on the web quickly by converting your shapefiles to KML for display in Google Earth, Google Maps, or Bing Maps.
Here is a quick example of showing off GIS data in Google's App Engine platform with Google Earth. It's important to note that this capability is essentially free. Google will host your spatial application. All you have to do is put it together.
Shapefiles in in Google's App Engine (select the Shape2Earth layers on the right).