Was your roomate irawasome?

It wasn't. My roommate is Colombian and has lots of raunchy sex and uses too much cologne and showers five times a day (I am not making any of this up).

Do what you'd do with other trash too: to your neighbor's lawn or trash bin. Then it is his problem.

Do you own your home?
Does it have a solid-poured foundation, a basement, or a crawlspace?
If it has a crawlspace, you may just be able to shove it under your house if there's room. Many crawlspaces are far too narrow to actually provide any access. Also, you may encounter a vermin problem as the body decomposes.
If you have a solid foundation or a basement, it's possible to just bury it underneath your house, but that depends on how sturdy your house is, and how much you're willing to compromise its structural integrity.

I don't own the house I live in, sadly. I'm thinking of hiring some people to help me dispose of the body though. As a general rule, how many people should know about a dead body at any given point?

Hmm, I suppose I'll keep it strictly in-house then.

In the words of Ben Franklin, "Three can keep a secret, if two of them are dead." I've attached a work by Howard Pyle which is related.

Basically, you're free to involve as many people as you'd like to help you, but at the end of the day, you've just got more bodies to take care of. If you're going to recruit others to help you, it's best to gather undesirables, and have their final act to be to prepare their own graves. If they won't be missed, you're less likely to have problems later. It's still a very risky business to bring others into, however.

Status update: I've managed to clear out the smell of the rotting flesh with some Febreze. I'm thinking abandoned quarry, but I'll have to brave my phobia of dual carriageways to get there.

That was my thought. I'm guessing the credit cards are still going to be good until the deceased is found or declared dead.

How about a coffin?

What, like one of the riff-raff?

Actually, the best and safest way to dispose a body is to get some of those "body waste"barrels that your local hospital uses. They are not consider "restricted" so you can buy them in just about every decent hardware/general surpluss store. Prepare a cutting room, cut up the body in fitting pieces, stick everything (including tools and plastic sheets into those boxes) and seal them.

Then bring them into the hospital and place them close to the morgue. The Hospital staff is forbidden to open them (due to infections and whatnot). They will be incinerated at extremly high temperatures without ever being opened again. All traces of the body gone forever.

Even if they can prove you brought those containers to the hospita, there is nothing they can do as all evidence has been utterly destroyed.

To be fair, it seems he didn't waste the whole body, he said he had a Fleshlight. :P
(Although I don't want to know what body parts he used for it specifically.)

Watch this episode of Archer. That might help.

http://www.imdb.com/title/tt2207831/