I am a chemist, and work with carbon. I have always wanted my ashes to be turned into a graphite target, for people in lab to use. That way, I can still be involved in experiements!
This firm took my idea, and made it better:
http://news.bbc.co.uk/1/hi/world/americas/2209799.stm
Basically, "A US firm says it will turn your cremated ashes into a diamond for the loved ones you leave behind to cherish."
That sounds awesome.