Meccano Dancing (Here We Go!). With Apologies to XTC.

I had some Erector Set materials when I was a kid (that being the US version of Meccano). It's a shame they went the way of "dumbing down" some years ago and have now pretty much vanished. Lego seems to do well (not sure about the current state of Lego's Mindstorms line of more advanced—and more expensive—robotic sets), but Meccano (Erector) was definitely in an interesting class of it's own. Here's Sir Arthur C. Clarke talking about Meccano (he also commented once that he had become wealthy enough to finally buy every set he ever wanted to have!):

In an article by Lord Taylor published in the Christmas 1978 edition of the British Medical Journal, the author describes a medical complaint known as the "Presenile Meccano Syndrome." The "victims" of this obsession apparently fall into the affluent middle-age category, people who are able to buy huge Meccano outfits and indulge themselves after possibly many years of not being able to afford to do this.

In two out of three cases, the gentlemen concerned are content to gaze at their outfits through the cellophane wrappings, while the third, who has probably never constructed a Meccano model in his life, delights in dismantling the models of others and very carefully replacing the parts in the appropriate compartments of the carton.

Well, I have some good news for the eminent medic. There's a complete cure for the Meccano Syndrome: it's called a Personal Computer...Unfortunately, the cure is much deadlier than the disease.

(Arthur C. Clarke, Greetings, Carbon-Based Bipeds!)

(2015 Update: The fascination continues.)