I always loved quirky pointing devices. From things like wowpen eco (only 2 buttons + scroll wheel) to all sorts of trackballs. Out of them, Logitech Cordless Optical TrackMan required me to use all fingers but unfortunately, it broke and can only be bought on ebay for a fortune.
One more thing to maybe keep on yout radar is a KeyMouse.
Sure, It's on pre-orders for now so no idea how well it works until we get reviews. But the thing is, your request of buttons for all fingers is fulfilled here. On both hands even.
But it's expensive as hell so don't buy it until it's out and more is known about it. <-That goes for EVERYONE. as I'm sure Ross won't buy anything he's not sure of when it has this kind of price.
Oh and the Claw was great. While I was still playing Quake3Arena a lot. Last time i saw it, it was somewhere in my garage. And I'm sure it still works.