Waterproof Camera Housings

So I got to thinking again how nice it would be to be able to take my camera into the surf, out in a lake, etc....but there are so many choices...

My brother has a Canon branded case that will fit an old A40 or A20, but that is only good up to 2 megapixels, which is fine for most purposes...and I can get a new A40 for $50 or less. (his got dropped in the water and mine died from natural causes)

But there's also the option of getting a case for my A510, there's the canon WP-DC60 but that's over $150...case costing more than my camera is frightening.

Now what I'm wondering, is if anybody has tried something like the generic [URL="http://www.alibaba.com/catalog/11144247/Camera_Waterproof_Case.html"]WP-50DiCAPac/URL] for a measly $35. It looks a lot like a fancy ziploc bag to me, but it looks a lot less bulky than the canon WP-DC60 and has a heck of a lot more room for upgrading the camera (the wp60 is only good up to what, the A520?)

I wonder if the quality is any good and how much control this impedes. I figure if i'm out surfing, I can set it to underwater or auto. The case might impede zoom also but hey, it's $35 and it might be better than just a waterproof disposable.

Your thoughts?

Bump before I try the generic one.

Never used one like that myself, but check B&H for similar bags by EWA Marine. They stock a lot of different models and EWA has been around for a while. If it were me, I'd probably feel more comfortable going that route - a lot of trust with a product like that! Thought about getting one myself but went for the new Olympus 720 SW which is waterproof to 10' without a housing.