Making flash photography more effective

On-board flashes on D-SLR cameras are limited in their use in lighting up a subject and so the purchase of an external flash becomes a necessity (or want in a lot of cases :) ) but still, even after bouncing the flash,the lighting still may be not right,so a diffuser accessorie might also be needed! This a great one...would like to find one or something similar in Australia!? HAve a look at this