My soon-to-be 4 year old ds2 is very much into mechanics and how things work. He can spend 10 minutes looking at the latch of the dishwasher or the locker at the gym trying to figure out how it works. He wants to know how anything and everything works and he wants to build, build, build! Most of his questions require me looking up the answer! The one trouble I have for finding toys for him is that he still has those chunky fingers that aren't quite what he wants them to be. At 3 1/2, his brother got his first lego set and ds2 wanted so badly to build, but was frustrated to the point of tears figuring out how to be gentle enough with them. Now, he's mostly fine with Legos.
Any experienced moms of future engineers have ideas for a great gift? Something to build, create, make go, a book about how things work in a language appropriate for a 4 year old?