They work great, don't they?
The dairy supply place a few blocks from my house throws out the old crates that are slightly damaged or have been hit by graffiti. Whenever I see a usable crate in 1 piece I grab it, they usually dump the ones they don't want the night before the recycling truck comes by, and sometimes they do have to be hosed down.
Fortunately, after a good cleaning they stack very nicely, and keep the collection organized, if not immediately accessible.