Donate the body to science. Like pre-planning a funeral, this is a decision best made before death. It may sound creepy to some, but there's no question that people who leave their body to medical science are doing a service, and most medical research facilities that accept bodies handle all of the transportation and burial costs. In fact, many research facilities offer an annual memorial service for those who have donated their body to medical science, and if you prefer not to receive an urn of ashes, many will put the body in a repository for bones or bodies of the dead.

But do your research first. For starters, donating your body to science is different than donating organs (since the organs are taken but the body sticks around for the funeral), and if you donate your body, you can't also be an organ donor (researchers don't want your body without the organs).

Family members may get your remains fairly quickly. MedCure, based in Portland, Ore., will send the cremated ashes to family members four to six weeks after death. Science Care, based in Phoenix, returns them three to five weeks later. But many facilities won't return the remains for two or three years, which may bother some family members who are looking for the closure of scattering ashes.

You could not claim the body. Nobody is suggesting you don't claim a loved one. But if you're low on funds and you can't see any other option for a distant relative or acquaintance, unclaimed bodies are taken care of by the local or state government.

If you go that route, "you'll never know what happened to them," says a pained-sounding Mannix.

Often, unclaimed bodies are cremated by the local government and the remains are held until something can be done with them. Every year, Los Angeles holds a mass funeral for unclaimed bodies; last December, mourners, chaplains, and county officials said goodbye to 1,656 people, most of whom died in 2009. It's also common for an unclaimed body to be offered to a medical school for research or perhaps sent to a body farm, where human decomposition is studied.

In which case, you may be better off not knowing what happened.

Click here to become a fan of MSN Money on Facebook

More from U.S. News & World Report: