You combine it with two other blocks: and white one with a red "f", and a red one with a white "f". Once you have all 3 in your inventory, something magical will happen.
Keep squeezing those chickens and nibbling those piggies!
It's a very geeky programming reference. Before there was "Flash", there was something called FutureWave which was a separate company eventually bought out by Adobe. The compiler generated ShockWave Flash files !
Of course, this will all be meaningless in 12-18 months since Adobe has been unable to create a compelling (aka runs fast w/o killing the battery) Flash plugin for mobile devices, so expect to see "HTML5" replace it entirely.