When using the Google’s My Maps feature you can display multiple maps at once simply by ticking the boxes, however the ‘Link to this Map’ will only ever include 1 map, so you can’t easily send a group of maps to someone.
… So a new script – this time under the gokml.net banner – for creating a ‘container’ KML that simply opens a bunch of maps at once – this KML is openabe in Google Earth, but also you can share the link so others can see your batch of My Maps at once in Google Maps.
As a total aside I notice My Maps, now sport a (Geo)RSS feed