[imperialWicket]

Kiwi Crates (and Koala - haven't tired the older age targeting boxes) are excellent, our 4 and 5 year olds love them. The results don't have a lot of longevity, at least for the Kiwi crates, but they consume an afternoon+ and involve a lot of productive-feeling efforts.

I have been thinking about genius box, the young scientist club, explorabox, and agent ribbit, too. There is so much overlap in a lot of these that it's difficult to commit to multiple without just ending up with duplicates. That probably wouldn't be entirely bad, but it's mildly annoying. Also, not all of these get down to the 3-4 yr range, but maybe something to think about in the context of the impending TinkerCrate subscription.

http://www.geniusbox.me/

http://theyoungscientistsclub.com/

http://www.explorabox.org/

http://agentribbit.com/