I have seen alot of discussion on belt bags, and I wanted to mention that I have used Garden tool bags, which are quite handy as they have many pockets. The last one I had had three pockets and two loops and was really useful. I hope these links are correct, it is just an example of the sort of thing it is. As mine has a good clip-buckle belt, I also carried my BOAB on it.
http://compare.ebay.co.uk/like/150612550992?clk_rvr_id=465933451123
http://www.supaprice.co.uk/p/result.jsp?ga=uk16&q=gardening+tool+belts
http://compare.ebay.co.uk/like/150612550992?clk_rvr_id=465933451123
http://www.supaprice.co.uk/p/result.jsp?ga=uk16&q=gardening+tool+belts