In the UK you can get them from here - http://www.bellwood.co.uk/flashbrackets.shtml
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I do think they look fab, as brackets go, and very nearly got one, but I am really concerned that the weight of a 1D3, 70-300/2.8IS (or even 24-70/2.8), 580EX and the bracket would be more than I would want to bear for hours on end at a wedding. Since I often shoot with two bodies on the go at once, which one would get the bracket, or should I have two? Also, if you mix body sized - gripped/ungripped, or gripped + 1 series - then you will need two versions of the twisty turny plate thing and that adds to the cost.
I totally understand the benefits a bracket can bring, but cost, weight and bulk (one of those things will not fit easily into your typical camera bag) are the things I am less happy with. I do have two cheap eBay brackets of differing designs, one of which is quite compact and light, but I use neither of them.
Instead I go for the "abetterbouncecard
" approach for indoors. Outdoors the direct flash for fill is just fine coming in from a slight side angle.