Bill wrote:

We had a small break-in; the perp left a bunch of these, either
intentionally or not, scattered around the scene of the crime.

Does anyone know what this thing is or does? I thought it might be to
slow water-flow within a hose, but I'm not sure.

Thanks for your ideas. Here are the photos:

http://photos.yahoo.com/billgangley2005




Yup, that's a bio ball for pond filtration.