It is pretty apparent that the kittens are going to be permanent residents, and in true Glenbrook Valley fashion, we have to provide them with some swank, especially in the bathroom department.
The challenge, like all challenges in GBV, is deciding whether to upgrade or renovate. Modkat offers a pricey, but easy upgrade option: http://www.modkat.com/. The turquoise is pretty nice.
IkeaHacker, though, has a fabulous idea: http://ikeahacker.blogspot.com/2009/05/put-cat-litter-box-at-entryway.html. This, though, looks like a major undertaking, and not any cheaper.