Can I be an organ donor and still be buried in an Orthodox cemetery?

A person who saves someone’s life by donating an organ hes done a great Mitzvah. The Halachic problem that arises is that if the organ is essential for the donor’s life, taking it while the donor is still alive is halachically an act of murder. Therefore, the issue that needs be addressed when discussing organ donations is how to establish the donor’s time of death. The Halachah does not recognize the common concept of "brain death" as establishing the time of death of the donor. And by the time a person is Halachically dead (no longer breathing, and heart no longer beating), the person’s vital organs may no longer be useful for transplanting.
It is important to realize that "quality of life" issues are not relevant to this question. Killing a person who has only five minutes to live is just as much murder as killing a person who has 70 years to live.
Donating an organ such as a kidney, which is not essential for the donor’s life, or donating bone marrow, not only is not a sin, but is a tremendous Mitzvah. Even if you are donating a heart or other vital organ, you are not actively doing a sin. At worst, the doctor harvesting the organ is sinning, but there would be no reason to exclude you from burial in a Jewish cemetery. However, if you are contemplating making such a donation, you should consult a Rabbi who is knowledgable in both Halachah and Medical Ethics.