Nice one!
On Chilternburts feedback - looks the same on IE Firefox. If you want to try something else then try fix the background to the bottom right and don't repeat (put this in the 'body' style):
background-repeat: no-repeat;
background-attachment: fixed;
background-position: 100% 100%;
Fade the image to white (top & left borders) so there are no hard image edges. Use a photoshop mask to do this, using the gradient tool.
