Cut-and-pasted from Darlene..
Trying to find a map mashup you spotted last week or wondering if there's one related to your favourite topic? MapShark can help you find it.

See also:
YourGMap is a simple and straightforward web application for building a Google map mashup. Enter the addresses of particular locations one at a time, choose the type of pushpin, and description and notes or even a photo, and click preview/publish and create an account.

Build a Google map mashup with CommunityWalk by point and click and adding in some information from places you've worked, cities you've visited, historic buildings in your town, walking tours for visitors.