If you own the Panasonic LX5 you might be interested to take a look at the new Nauticam underwater housing. It has a depth rating of 75 meters and will sell for $950. You can read the full specs here: http://nauticamusa.com/. It’s a lot more expensive than the Ikelite housing (Click here ot see that item on eBay) which costs $545 only. I am not an expert and I don’t know if the price difference is justified because of better specs.
Olympus XZ-1 user do have an even cheaper alternative: The Olympus PT-050 which is available for around $300 (300 Euro) at Amazon, Olympus US store, Adorama, B&H, eBay.
Olympus E-PL1 user can get the Olympus PT-EP01 at Amazon, Olympus US store, Adorama, B&H, eBay.
and the E-PL2 user can get the Olympus PT-EP03 at Amazon, Olympus US store, Adorama, B&H, eBay.