Typically if your living in wales your going to see a hawk. These are used for training new pilots in fast-jet manauvering and control.
If you look closer you can see that its the instructor in the back of the jet is doing the flying on this pass
This is an Alphajet - Not used for training this time, this was one the QinetiQ jets from (I think) RAF Boscombe.
This pilot was obviously having fun as he tipped his wings towards the photographers, pushing it past the vertical so much that if you look at the high resolution version of this photo you can see the QinetiQ markings on the far side of the cockpit.
The best place I have been for these photographs is a place called the Mach Loop in Mid Wales. It is at Corris, not far from Machyllneth.
Low flying aircraft prove to be one of the most challenging subjects to photograph. Typically you need a camera with a fast autofocus and some very decent quality glass* in front. Having a camera with virtually no shutter lag and a high rate of frames per second is pretty important too. I use a Canon 30D with a Battery Grip and a Canon 300 F/4L Lens.