You should have a look at Circuit Scribe http://www.circuitscribe.com/ http://www.circuitscribe.com/ It's basically pens filled with some kind of metallic ink

You should have a look at Circuit Scribe http://www.circuitscribe.com/ http://www.circuitscribe.com/ It's basically pens filled with some kind of metallic ink that conducts electricity. It comes with "blocks" you place on a paper sheet. You use the pens to connect the blocks.