This function will allow user digitize objects base on the shared border. It is not like the Replace sketch function because user only need some share segments. It might need like new freehand function in Arcgis 10 but it will snap to the existing feature. This makes it easier to digitize objects that share a border because you don't have to re-digitize the shared border. Can use this feature to trace an existing polygon/polyline would be great.
