OK, This might be it for the elaborate wooden toys for a while. I don't know how I can surpass the Naef Gloggomobil. It's a totally programmable barrel organ, a giant, wooden version of that little metal cylinder that drives a music box. You--or your child 2 years or older, or more likely, the two of you together--compose your songs by placing pegs in the rotating wheel, which triggers the little mallets to strike the xylophone. You can play the xylophone by itself, too. The whole rig's 13x14x7, about the size of a toaster oven or that stack of catalogues that needs culling.

From what I understand, Naef only makes 100 of these Gloggomobils every two years. And there's at least one available on this Swiss toy store's page, with a note that it was added to the inventory on Jan. 26, 2005. Which means during this 2-year cycle, there are not yet a hundred people in the world who've dropped $930 on a Gloggomobil with hopes of nurturing their childrens' musical composition abilities.

Naef Gloggomobil by Herbert Bachli, 980 Swiss Francs [spielzueg.ch]
SeeTouchThink had the Gloggomobil for sale at one point for $US930, but their site's all wack at the moment. [seetouchthink.com]