After you make your make a map created in ArcExplorer public, you can use it and another public map to create this embeddable web application (under "share - make a web application" in ArcOnline map viewer).
You can use these web applications with your ArcExplorer map by saving your map and opening it in ArcOnline, then using "share" to put the map up on the web, then share again to select a template and follow the template wizard.
To obtain latitude and longitude coordinates in decimal degrees, search for your place name, then click the matching entry.
When the pointer appears on the map, click on it. The coordinates in decimal degrees will display on the left side.