Google Wave maps gadget lets participants of a wave to collaboratively edit map using markers & other tools. Participants can add tittle & description to their markers. Edits by a user will be visible to other participants once user clicks save. This gadget is very different from Trippy. This gadget is multi purpose which you can play around to share your place, route etc with friends. But, Trippy is more concentrated on planning a trip, creating an itinerary ..etc.

Though options to access Google My Maps & save created map to Google My Maps should have been awesome.

Gadget XML URL: http://google-wave-resources.googlecode.com/svn/trunk/samples/extensions/gadgets/mappy/mappy.xml