My brother is about to renovate the kitchen in his Austin home. The style of the homes there is a casual mix of modern and rustic. As a result, he is leaning towards materials like slate and concrete.
He just sent me a link to the Buddy Rhodes Web site, which features concrete mix and concrete molds for creating your own decorative counter tops and floors.
The company sells 4 different sink molds (this is the work of the oval mold) from $640 - $800. I love the results, but this is work I will have leave to the more adventurous among you.