The ArcGIS Online Webmap Switcher allows users to dynamically switch from a selection of webmaps served out in a developer-defined group. You also have the ability through this widget to add in data directly from your ArcGIS Online account into the webmap.
You will need to manually type in the group id number in line 38 of the widget.js file to set it to your own group.
Keep in mind that this is my first attempt at a widget.
I'm hoping to update it further by adding a search utility as well.