Sometimes you could find useful let your flash still in a place and take your photos all around. This is pretty true in case you're making a 360° panoramic photo. You can't move your light source from a shot to the other because in assembly process you'll see the differences in the shadows.
You'll work better with a slave-flash, but also a cable connected one is good. Then you need a diffuser to make the light reach all 360° around you. You can build it yourself, ops you have to built yourself, because I think it doesn't exist! ...if it doesn't exist it shouldn't be so useful, you say... right, or maybe I'm a genius! ;-)
Anyway, this is what Instructables is intended to, let's build it!

Step 1: The Glittering Container

You're lucky because you can use the same container which is part of the Flash Grid Snoot (and after the efforts you had to put into finding it among all the hand soaps it's better it attends to something else).
Sorry if I post some images you've already found on the other tutorial... I could have posted all in one, but I though it also could became annoying.

Step 2: Let's Heat It

For the ones who hadn't the pleasure to read my other Instructable (go to read it asap!) you have to cut the container (make it about 8 cm long) and to heat it on a flame, so it fits the flash head. Remember to wrap the head of your flash with some package tape. Then twirl continuously it over the flame (the container, not the flash!!) so it shoudn't melt.

Step 3: And Fit It

Wrapping the flash head with packaging tape you'll obtain a double goal. First you shouldn't damage your (very) expensive flash and second you'll have some thickness to make the diffuser fit better to it.
Once your container is soft you could try to fit it onto your flash, then wait it gets solid, take it away and remove the tape to check it fits with the right tension. It's better it's a little loose because my plastic tends a little to recover original form.

Step 4: The Mirror

Now you have to cut a piece of reflective paper, but any reflective material is good, probably it shouldn't make any difference if it's even white.
This reflector has to be folded at a 90° angle, so that it reflect light to the inside of the container walls. To found the right shape you have to try with a paper sheet, cut some shapes 'till you find the right one. if you want to have a straws grid snoot too, this reflector has to stay in place alone, so it shoudn't be too loose.
I've attached two pieces of transparent tape to help put it on place.

Step 5: Everything Is Ready...

Now you have a 360° flash diffuser and you can test it in centre of a room. In 360° photography you could put it on the floor under the tripod, if the tripod legs are enough thin they should't make a bad shadow, but in case you could always turn for each photo the tripod so there is no leg under your lens.

Step 6: ...for the Test!

I show you the effect of this diffuser set on the floor and on a tripod. Maybe the 360° effect is more clear in first photo of the Instructable. I've kept flash power low to show better light diffuson. I hope this should be useful.