i use a small shower caddy to house the litter scoop and my other litter supplies. it's big enough to hold the litter scoop, the spoon & paintscraper for stuff i can't get with the scoop, the roll of 4 gal bags i use, baking soda, and the container of method wipes for if someone pees on the side of the box. the best part? the caddy cost a dollar, check your local dollar stores for one.

the caddy is compartmentalized too, so the stuff that goes in the litter doesn't have to touch the other stuff like the bags & wipes. this also makes it easier as i go around to the other litter boxes.