I started to think about a music clip with some underwater images. but nothing so deep, just one or two meters down on a pool. maybe it would be better to use a cheap camera like an old canon hv20 for that kind of risk. but i do not know if there are cheap underwater housing for the hv20.

It's probably okay for that. Just test first. Put a bunch of toilet paper (unused) in the bag and submerge.

Dicapac works. It´s cheap enough so I wouldn´t trust any no-brand stuff. I´ve submerged a 7d in their dslr case which can be used down to 5m. (compact bags work down to 10m) No need for stones - just do a thorough test first, TP works well for that. Don´t leave the bag out in the sun and take care when opening!

Btw, exposing / focusing / handling is not easy. Try to set up for a minimum of underwater control.

nice shots on flickr! thanks guys for the tips.

I´ve used both the wp-610 (with an LX3) and wp-s10 (with a 7d).. I´d go for the wp-h10 if you know you will use the pancake – the dslr cases are pretty lofty and makes a good fit for zooms / physically longer lenses.

Can second what @andyharris said about seals; it´s good to take care when both closing and opening.. It´s also a good idea to always have a bit of TP inside when making a seal; should a small leak happen for some reason you´ll have a better chance of knowing about it / can avoid drenching your camera.

Another thing; make sure you´ve done tests of how your camera "see" underwater, especially if doing a serious shoot. It´s very hard to make any adjustments while underwater so you´ll want to set everything up beforehand as well as possible.