Not all religions believe in pumping in the formaldehyde, thus preserving the body better than McDonald's fries and Big Mac. (For a video, see below.) Nor do they believe in keeping the body around for a "viewing" for a week or longer, or putting them in a piece of furniture that would put your California King to shame.
Example (just one of many):
"Jewish burials take place as quickly as possible, following a principle of honoring the dead (k'vod hamet). Only if immediate relatives cannot arrive in time from abroad, or there is not enough time for burial before Shabbat or a holiday, are burials postponed for a day. Anything less is considered a "humiliation of the dead," Greenberg explains.
"If you don't already have funeral plots purchased, you or a representative will need to contact a cemetery to purchase a plot. You will also need to contact a funeral parlor to transfer the body and schedule the time of the funeral. Jewish law mandates a simple pine box, so although you may need to choose a plot, you don't need to concern yourself with elaborate decisions about coffins. Or with cremation or embalming, which are forbidden by Jewish law (halacha), Greenberg writes. However, many Reform rabbis will officiate at funerals involving cremation and embalming, according to Reform Rabbi Steven Chester."
See
http://www.jewishfederations.org/funeral-customs.aspx
And for the less squeemish out there, human decomposition: