Thai web development company Computerlogy are one of the Google Maps API developers featured on Google's new MoreThanAMap website.
When flooding affected much of Thailand last year Computerlogy released a handy Google Maps based application that allowed users to check the elevation of any address. Check Elevation has an easy to use interface. Users can search for an address and can simply click on any point on the map to find the elevation at that point.
The information window that opens to show the elevation details also includes two buttons to share the elevation at that location via Twitter or Facebook. This allowed users to check the elevations of their friends and family's homes and be able to easily share and pass on the information.
If you want to include elevation information in your own Google Maps then check out the Elevation Service section of the Google Maps API.