If you are using shelf pins for the button, I would figure some o-rings on them would help seal them up. Place the orings on the portion of the pin inside the case but outside the lip, if that makes sense. Would make it a tad more water resistant, I would think. Or a layer of liquid electrical tape? As for the screen, I'm gonna use just some cheapo screen protectors over the face of the screen and tape it all down snug to the case. Hopefully its tight enough for me. You may need more water resistance than I do, but I figure this will be good enough for now. I'm interested to see what others say, though. And custom silicone cases would be BADAAAASS, I'll have to look into that myself.