hey mike-
thanks again for your help!
For a webapp newbie, it can get quite confusing, but the SW user conf. really summed things up:
1. Flex/Silverlight web viewer apps are free to download, they enable you to configure a custom website viewer in the language of your choosing.
-the viewer connects to SERVICES only, so, you either have to use freely provided data/imagery services from ArcGIS online, OR have an installation of ArcGIS for Server
2. You can also create a basic map using the ArcGIS explorer or web viewer via ArcGIS Online. There is one slight advantage to using ArcGIS Online; you can upload .zipped shapefiles to your map. Otherwise, ArcGIS for Server is required.
3. If your not liking the ArcGIS Explorer or web view maps from ArcGIS online, you can create the share button while on the map, and use a template. This template can be downloaded to your local server and hosted, OR can remain on ArcGIS Online.