Teaching hiragana to a 9 year old

My son is 9 and speaks Japanese with his mum around the house and watches a fair amount of anime (mostly One Piece). The challenge we face is getting him to at least be able to relate what he hears to what he can see. In the first instance this means getting him comfortable with kana.

When I learnt it didn't take too long, just a couple of weeks. I was in Japan and basically began by learning katakana to read loan words (I knew them) then to hiragana to read the station signs on the non-JR platforms. Tomo doesn't have that immersive environment outside the house to support and reward him. He also lacks the adult intrinsic motivation that drove me to basically write out a line from the table a dozen times a day, between every lesson, until I could write the whole thing. So what do I do to create the conditions for victory?

Obviously the basis of learning this sort of thing is rote - there's no better way, but there are improved tools available. For a start we have the Nintendo DS for which we have a few games that are educational (good old Doraemon). I've managed to find a few games online that have Japanese as a context, with learning part of the game, for example this insect game from Okochama. And no surprise to see Shimajiro toward the top of the results either. If I find better ones I'll add them here too.

I'm going to need some flash cards, so these in printed and hand-written styles will be good. For the record, I won't bother with the romaji sides as that defeats my goal of making the characters natural first-language.

As an incentive I think I will use the old financial one. It has seen benefits this year in other areas of endeavour, so a simple goal to be able to write out the kana in each form for a cash reward should do the trick.

The aim will be to get recognition up first, then selection, then reproduction, controlled, then freer. Usual rules really for any learning experience. I will report back on this.