My favorite diffuser / modifier for off-camera flash, is the Lastolite Ezybox 24x24 for speed lights (affiliate). The Lastolite Ezybox has featured often on the Tangents blog. (Here is the review). It's easy to use and super-easy to set up. And in its original configuration, folds up to a surprisingly small bundle.
The good news for photographers who have been curious about the Lastolite Ezybox, is that Impact now makes a softbox - the Impact Quikbox 24x24 softbox (affiliate), which is virtually identical, at a lower Read more inside...