We used to have three cats, one of which was a nervous pee-er. He has since gone to a much quieter home where he has never had a peeing incident (aka - no toddlers). I have mixed feelings about that still, I'm happy that he's happy, but I still miss him. <sigh>
Anyhow - Max and I built him this cat litter bench last year. We used all wood that I found in the garage, left over from the previous homeowners. I don't have the pictures of the completed box, but imagine it with a hinged lid on top. We made sure that the slats were spaced for ventilation as well as kitty viewpoints (one cat likes to make sure no one will sneak up on her). The bench was much bigger than the litter pan, which was nice because it led to less litter tracking, and there was room for the extra litter, scoop, etc.
Max LOVED helping me assemble this. :) He called it his coyote hole (he was calling the cats coyotes at that point, quite the imagination), and the hardest part of the whole project was telling him that he couldn't play in it anymore.
And, like I mentioned, I built it for the cat that no longer lives with us. The new owners weren't interested in the bench, and the other two didn't really use it. So it sat in the garage until the yard sale, where another cat owner was more than happy to buy it for her furry babies.