The diffusers are very cheap to buy on Ebay, the last one only cost me £5 and that included postage.
The main thing I like about them is that they are rounded at the edges so the light is spread. When the air is let out they will fold flat to go into the camera bag so they take up very little space.
The flower is only 5mm in size and is called Black Medic (Medicago lupulina) Very similar to Hop Trefoil in appearance and size, but can be told by the little point on the end of the leaf.