We have three cats and have been using one of these for several months. Works great -- no odor at all! Basically, it's like a DiaperGenie for cat poo.
"Litter Locker II Cat Litter Disposal System is a complete and hygienic soiled litter disposal solution. This system provides an easy, odorless, hygienic way to dispose of waste creating a healthier, more pleasant home environment. The Litter Locker II Cat Litter Disposal System reduces odor, makes clean-up quick and easy, hygienically seals soiled litter clumps, and reduces trips to the garbage. Simply scoop litter as usual and dispose in the Litter Locker II, pull and release the handle to lock away clumps, odor and bacteria. Litter bag refill cartridges last up to two months per cat and the odorless barrier bags keeps odors from escaping.
* The Litter Locker II comes complete with a refill bag cartridge, litter scoop and litter scoop holder that can hang directly on the Litter Locker II."