It typically takes me under an hour to get a new interactive widget going, and most of that time is spent tweaking the appearance, which is rather enjoyable. It may take you longer the first time you do it, but by following the example of existing Morphs I suspect you'll have something going in under a day. – JohnMaloney, March 2003
See also
CrossMorph for a new subclass of Morph which only overrides the implementation of drawOn: