To display a map on a webpage, you can often use directly the api of a commercial provider (such as cloudmade Web Maps Lite or google maps api). The other solution is to use OpenLayers, a free javascript library to display embed maps in a web document.

With OpenLayers, it's quite easy to draw a path on the map. But unfortunately, once a point has been added to the path, it's not possible to modify or delete it. This is possible with web maps lite, as can be seen in this distance calculator. I really like the ergonomy of the web maps lite path creator, and wanted to have something similar for OpenLayers.

So, I wrote ModifiablePath, a class to improve OpenLayers path creator. So, when creating a path with this handler, you can move, delete or even add new points. I've put a demo online, and code is available at github.