I love a clever repurposing project that lightens the landfill load and that looks great to boot. Check this one out. Flower pots made out of repurposed tires. From the photo, it looks like you can make a doggie bed, too.
Here are the directions:
Take an old tire that is still mounted to the rim. This method will not work if the tire doesn't have a rim on it, as the rim is what holds it together.
Make zig-zag or scalloped cuts approximately eight to twelve inches from the rim on one side of the tire, depending on the size of the tire. (Note that these cuts are only on the flat part of the tire near the rim, not onto the area where the treads are.) Make the cuts all the way around the tire so that the tire is separated into two pieces, held together by the rim. Remember, do not take the tire off the rim.
Turn the tire inside-out. The easiest way to do this is to put the tire on a stump (or stool or something like it), with the cuts facing up. Take the outer part of the cut tire, and pull it out and downward to turn it inside out. It's hard at first, but once you get it going, goes fairly smoothly.
Once you've turned it inside-out, you should wind up with one very large section (which becomes the plant holder part of the planter) and one very small tire section (which becomes the base of the planter). The holes in the rim become the drainage holes for the plant.
At this point, if desired, designs can be painted on the outside of the large part of the planter. Tole designs work nicely on this.
Put some dirt or fertilizer inside the large section of the tire.
Plant your little plants or flower plants in it. Water it.