A few colleagues and I were talking about developing a water transportation hands-on activity for kids using Lego. In serching for cool Lego stuff (yes, that's what I do for work) I came across this and could not contain my excitement! With a 3D printer (see http://en.wikipedia.org/wiki/3D_printing, I know of 3D printing because we have it in the dept), Carnegie Mellon Professor Golan Levin developed the Free Universal Constrauction Kit - "A collection of nearly 80 adapter bricks that enable complete interoperability between ten popular children's construction toys."
While some people were worried about legal concerns, so far none of the companies have reaised any issues with this. So until then, the models are available for download at http://fffff.at/free-universal-construction-kit/- all you will need then is to print these out with a 3D printer...
"The Free Universal Construction Kit (http://fffff.at/free-universal-construction-kit) is a collection of nearly 80 adapter bricks that enable complete interoperability between ten popular children's construction toys."
Via Theresa Liao