Just my attempt at making a diffuser/bouncer for my 430ex. I took an old food container and cut ahole in the base to fit the falsh and kept the lid. I then pasted 2 layers of tracing paper on the top and inserted on ring into the bowl part making sure it dosent cover over the flash. The circle of foil can be inserted into the top part of the bowl and covered with the top part to reflect the light back down in the event the celing is too high.
This is not meant to be used as a direct diffuser but rather as an 'omnibounce' of sorts.
Below are the results.
Without foil inserted
With foil inserted
As you can see the diffuser does lose quite a bit of light. All the pics were taken with FEL on manual and a timer release. Next, subject tests...