[tpiha]

Those old Meccano sets were awesome too, you can still find them on Ebay.

When he's older, radio controlled airplanes, cars, helicopters, boats.

You could probably have a general DIY attitude and build some toys for him with him.

This looks cool too:

https://www.kickstarter.com/projects/infento/infento-worlds-...

[orless]

Oh, yes, Meccano is a good hint. Requires different mechanical/fine motoric skills compared to Lego Technik/Fischertechnik.

As for Infento - looks very neat, a bit too "prepared" for my taste. We do such things from wood and stuff you can buy from the local hardware store. Here's an example of something we've built in a day:

https://twitter.com/orless/status/632590264964657152