Posts #9 & #10 describe different ways of using bricks, building down from the top.
I suspect the bricks have to be wedge shaped, you could push a rectangular brick out of the wall without disturbing the bricks round it.
sounds all too compicated for me, l like the idea of drilling a smallish bore 4 or 5" maybe, l see some people hammer a steel tube into the ground pull it back out remove the earth from the inside and repeat
theres a vid on here of this process
http://www.consallen.com/
at least this way you could do it yourself ??
l have a load of these galv steel tubes about 5" in diameter h'mmm
Robin would have to find a new home though




but l would sit happily on one of my excavators for hours and not see that as a waste of time
, so if you have an excavator as a toy you need to be able to use it, digging a hole and filling it in and then digging another and filling it in soon gets boring so l needed something meaningful to do with my excavator, an offroad or quad bike track was one of my first thoughts and being a law abiding citizen l wated to do it right and get planning permission, BIG mistake dont every tell the councill what you want to do as they will say NO whatever it is you want 
£600 for 10 minutes work
l have that letter framed on the wall, why ??