Yeah its up again... sorta. Tried to post reply, but I got the spinning wheel of death. PM reply might have gone through, but in case it didn't.
It depends on what you are trying to do.
The trace or outline or whatever it is function from Inkscape is only marginally okay for copying line art.
Sometimes for organic simple-ish shapes I'll photograph it from several angles and then manually trace it in ViaCAD with a combination of lines, arcs, and splines. The spline tool in ViaCAD is (in my opinion) a little better than the one in CamBam. Then I'll set scales (sometimes before) based on physically measuring the object. Then I'll us all those conglomerations (each one restricted to 2 dimensions) to try and create the 3D shape. I see lots of failures.
I recently (several months ago) picked up a 3D laser scanner, but I've been so busy its still in the box.
For mechanical items like 2D templates, adapter plates, and gaskets a light tablet and stylus can do an amazing job. Trace, 3 point interpolate, and locate with the stylus, and the offset of the stylus is known. This would be good for something like a gasket, control panel, etc.