Thanks for all the suggestions you guys. It's so nice to feel that you all care!
In the end I just put unit studies/library books and also double-checked that the State doesn't test or expect a test to be done on anything other than English and Math. So really, any other subject is open. My very lose plan all along has been to try and make sure he covers what they'd be doing in school anyway, but also try to keep things linked to a sense of chronology. On the side, he's also done a volcano kit, he's super into Sharks - so we've done the whole Shark Musuem, touch a shark, watch DVDs on sharks and bought the "take a shark apart anatomical" set.
The world list will be really helpful - thanks Kriston - and I will check out all the suggestions but the history linked one from Minnie might work right away - he's already into a few weeks work on Story of the World and I was wondering how to tie something science in with that to a greater extent. I mean, next week they mummify a chicken - so that counts right?
