The [Drawdio](http://web.media.mit.edu/~silver/drawdio/) (created by [Jay Silver](http://1derful.org/)) combines drawing with audio. You can get [kits](http://www.ladyada.net/make/drawdio/) to [build one](http://www.makershed.com/ProductDetails.asp?ProductCode=MKAD12), or you can [solder one up on stripboard](http://2ne1.com/drawdio/). But I wanted to make one without faffing with a soldering iron – using screw terminal block.
That counts out the use of integrated circuits like the 555 variants used in the traditional Drawdio…