Keepsake Ideas

Recently, a friend had to put down their pet dog which meant a lot to him and his family. I am trying to think of different ways or things that I could get that could be used to remember their pet by. I know they keep the ashes in a box which made me think of some type of urn.
   
Wondering if anyone has come across something that works for them in such a situation?
   
thanks
   
tallan