Snapping to a line feature and digitizing along the line from a start to end point

[masonb]

I need a tool for selecting an existing line feature and then snapping to it using an edit tool and then digitizing along it from a start point to an end point. Does a tool like this exist already? If not, can someone create it?

[fredj]

This is what you're looking for: http://openlayers.org/dev/examples/snapping.html