"I want to be buried in your backyard, and when the flowers grow just know you're still in my heart..." - Nightmare of You
As someone who has become unwittingly fascinated by current customs in pet memorials, I think these 100% biodegradable urns by Limbo-Zoo are some of my most interesting finds yet. Although not quite as controversial as having your cat mummified, or creating a portrait out of your pet's ashes, the Geos Urn, which is made of all natural ingredients, can be buried with the lid removed to produce a tree. The fertile ashes along with the nutrients found in the urn will help the tree grow, thus allowing your beloved kitty to live on forever in nature. Intense!
What's more, if your cat was more fond of playing with the faucet than hanging out in the backyard, there's also the Samsara model that is made of sand so it can be reintegrated into a lake or river, or the Nu Zoo, which is made out of salt so your departed feline can become one with the sea or ocean.
All three of the ecologically friendly urns are available for purchase on the Limbo website for under $100 each, and if you're wondering (admit it, you were!), they sell them for humans (sans paw print designs), too.