I think its ethical... now if someone was still alive who knew or was related to the pharoah, then it would be another matter.
Personally I have not decided yet, how I will end up...
So far I think that getting cremated, and then have ones bone fragments mechanically reduced to ashes - will be the best way to prevent any fucked up things happening to your "afterlife" (ex. your skull ending on someones bookshelf).
But donating my body to Gunther von Hagens and becoming a "modern" mummy is also appealing - only problem is that I do not know how he should display me yet... (sitting infront of a computer or fucking a female pornstar mummy ;-)))