Underwater Sport Housing
Wetpixel.com is also a great resource for discussing underwater housings, both for surf and diving variations. I went diving last year with a G11 and Canon450D and the SLR was amazing compared to the compact, particularly for sunburst effects and responsiveness for fast-moving fish.
For what its worth, I love my Sea&Sea housing...
|_F0A5334-Edit_small by Dester Wallaboo|
from Open Air Fashion Photography
|Old Harry's Rocks by John93Robertson|
from View from the top - Sea