Legos for modeling science ideas

Teaching non-majors science I've always been interested in how we represent science ideas. My goal is to give students a chance to visualize and express science ideas on their own. There are so many ways to go about this. 

Just before YouTube got started I devised a "metavisualization" curriculum based on metacognition and visualization. My objective for that project was to engage students in making videos that conveyed scientific ideas. Some of the vids were great. Most of them reflected the last-minute effort that undergraduates put into assignments. I decided to drop the project after watching too many bad videos. 

Last year I got an arts initiative grant from my school. I used it to get students to do more hands-on, less cookbook labs. Some of the labs involved experiments the students made themselves, like seeing how water behaved in various situation. Others involved building with zometools, a simple yet sophisticated, infinitely flexible building set. All of the labs asked students to observe and reflect mindfully on what they were experiencing. 

I want to build on these labs next year. I did some research into the work they're doing at the MIT Media Lab and found the philosophies of learning coming out of there in coherence with mine. Ideas like "serious play" and "lifelong kindergarten" appeal to exactly the kind of learning environment I'm trying to build. The Media Lab is also a proponent of Legos. 

So I ordered a couple if lego sets to see if I could build some models with them. I unpacked the sets yesterday and experimented with a few ideas I'd like my students to pursue. One was a model of a termite mound. I had enough blocks to do a partial model. 

Then I worked on a couple of ideas for modeling polymers. I guess the possibilities are endless but here are a couple. 

Finally, I did a little experiment with genetic drift in two populations. I think it worked pretty well. 

1. A single population with randomly distributed variations. 

2. Two populations randomly isolated from one another. 

3. The process of genetic drift over a period of time. (Surviving populations in front).  The result: new species?

If you've worked with Legos in a university setting I'd love to hear your experiences. Most important, how did students respond?