Something that he can play with by himself.
He's happy to read or play computer games, watch telly etc, but he doesn't really sit and play as such.
He enjoys lego, his match box cars, Hex Bug, playmobil etc, but I'm reluctant to keep adding to these as they don't capture his interest for that long.
I can add to his marble run.
He tends to like short-lived fun, like those dinosaur excavation kits, or grow you own [insert strange scientific thing].
He's LOVES football. A little goal I could pop up somewhere would be good I guess - would need to be really sturdy.
We do like playing board games together or doing jigsaws.