I know that they come back in an urn, but if it's not very nice, I may buy something special. /QUOTE]
Are you sure?
When my cat was cremated, the cremains came back in what looked like a tupperware box.
My advice to people who plan to keep the ashes is - ask your vet for the phone number of the people who will do the cremating. In our area, if you get in touch with them, they can direct you to a website where you can look at urns. You can then tell them what urn you want, and what you want engraved on a plaque for it. You will then get the cremains in the urn.
I found this out after the fact. I ordered the urn after I got the tupperware box. They expected me to transfer the cremains to it. It was extremely upsetting -- and I couldn't get the urn open. I ended up taking the urn and the tupperware box back to the vet, and had the cremains transferred there.