Love the clay pot people - I made a large one a few years ago but I'm still trying to find time to make a dog and cat as companions!
Another idea I found this morning - I'm always looking for bases to use for mosaics. Thought this was an easy method and cheap. I couldn't find any instructions but the photo is pretty self-explanatory. Pavers can be purchased at Lowes or Home Depot for less than $2.00, some landscape block adhesive and you're got a container to decorate and then plant!
http://pinterest.com/pin/22954...