Jon writes in with this awesome Radio flyer tiny trike power mod -
The stock Radio Flyer Tiny Trike has exactly 0 horsepower. We decided to fix that. So with a broken old saw, a new power tool battery, some bungee cords and wires we’ve made this thing go.
instructables : Multnomah County Chopper – Radio Flyer Tiny Trike Power Mod – Link.