The latest bag of goodies I've been tinkering with for Decker is WigglyKit: a collection of modules and contraptions that make it easier to add things like WigglyPaint to your own decks, including the particularly fancy wigglyModal contraption which gives you a slightly simplified version of the WigglyPaint drawing tools as a modal dialog box. You can try the WIP version here:
Important Note: the design of WigglyKit is subject to change, and the version of web-decker in the demo contains some bugfixes which are not reflected in the current release version of Decker (v1.45). I don't recommend using these to build anything substantial until the next Decker release- probably sometime next week.