Can anyone recommend a portable soft-box to use with Canon 580EX&EX2 speed-lights? If so, can you explain why you recommend it and if possible provide a link for purchase?
Finally, anyone have any thoughts on defusers? Fong, Lumetec (spelling), etc...?
Also, I recall there was a sight "strobes something" which had really great tutorials and videos on the endless ways to use strobes.
I use a 20" by 20" soft box that I picked up for $60. The flash mounts into the back of the box so that you can access the controls without removing the cover, as opposed to those that mount inside the soft box. It works so well that I now have 2. This soft box twists closed somewhat like a big reflector and a lot of people complain about getting it closed, but its easy once you get the hang of it and the whole thing is very portable. I think that it is made by Innerfit.
I use Photoflex softboxes. If you are searching for "speedlite specific" softboxes, you may be limiting yourself. There seems to be enough adapters out there now that most big-strobe softboxes can be adapted to small flashes.
I've got small, medium, and large Photoflex softboxes, and speedrings for both big strobes and speedlites. To use their softboxes with small flashes, search for their "basic speed ring" and "shoemount adapter." If you have big strobes, you can get speed rings for your strobes as well and use the same softboxes on both. They also make an adapter that'll let you use 2 speedlites with a softbox if you need more power.