The Saia API helps this first class less-than-a-truckload (LTL) carrier deliver by giving developers access to tracking information inside their applications. Rate quotes and pick up scheduling are also accessible. The API uses SOAP and XML, and is implemented using Microsoft's .NET Framework.
Geocoding involves converting a description of a physical address into coordinates that represent that location on a map to perform spatial analysis. This tutorial on the Google Maps APIs blog describes the two approaches to geocoding with Google Maps APIs, and when to use them.
Once you get beyond the most basic map mashups, you'll run into a problem with data storage and access, because you can't hard-code hundreds of markers. It's a problem that SimpleGeo wants to fix. And from the looks of their new platform, they've gone beyond expectations.