Mineral Tubs - What do you do with them?

[Cattlelow]

We have some empty mineral tubs that we need to do something with. I have about a half-dozen of them in use as water troughs for the calves. But what do you do with the tubs you can't find a use for? Any suggestions?

Now, I'm not any kind of bunny-loving tree hugger, but I don't want those plastic things around my pastures for the next two thousand years. :roll:

I've planted my tomatos in them this year. Seem to be doing great. Easier on my back in tubs. I need to find a use for the metal ones. Any suggestions?