The Religious Policeman provides absolutely the best ever discussion of those 72 virgins. Via Samizdata and Andrew Sullivan we get a nice YouTube video of a stand up comedian discussing the question but take it away Alhamedi:

"I have, however, wondered long and hard about those virgins. Let me share some of my theological speculation with you.

Firstly,
are there 72 virgins for each male, or 72 virgins, period? You see, if
it’s the latter, it sounds like a lot, but then there an awful lot of
men in Paradise, and the number is rising all the time. And if there
are only 72 to go round everyone, then we’re going to need some sort of
queueing system, which we’re not very good at. But let’s say we’re
better at queueing in Paradise, and we all take a numbered ticket, and
wait in line. Our ticket says 18 billion and something, and the display
says 3 billion and change, but not to worry, we’ve got eternity to play
with. Eventually, we’re near the head of the line. The thing is,
though, some of us are going to be more attractive to the virgins than
others. For
example, Salah Ad Din here on the left, perhaps known to you as
Saladin, was a mighty Middle Eastern warrior at the time of the
Crusades, and by all accounts was also sophisticated, civilized,
learned and very charming. So when he appears at the head of the line,
I’m sure our young virgin will experience a shiver of anticipation. But
if it’s our young Jihadi on the right, it could be a different story.
You see, he’s probably been blown up by a bomb, which tends to make a
bit of a mess. Sure, they’ll do some basic surgery to sew the various
bits together, but materials are limited up there, and there are limits
to what you can do with a silken thread and the beak of a Humming Bird.
When his number finally gets called, he’s going to be standing there,
trying to look his best. For most men, they’ll check their tie, and
perhaps quietly make sure that their fly is zipped up. On the other
hand, our unfortunate Jihadi is going to be trying to hold his
intestines in with the burnt-off stump of what was his hand. So that’s
the night that our virgin suddenly remembers that she needs to wash her
hair. Luck of the draw, my friend, take another ticket, go to the back
of the queue.

Alternatively, there could be 72 virgins for every
male. Sounds better? Think about it. There are 72 of them and just one
of you. They all have their needs and desires, both emotional and
physical. So how are you going to satisfy them? Well, "one at at a
time" is part of the answer. And you’ll need a rota system. Plus you’ll
need a bit of rest and recreation yourself. Let’s say you spend a night
with each? It’s going to take about 80 days before the virgin at the
back of the queue gets to the front. So let’s guess what sort of mood
she is going to be in, after nearly three months of waiting for some
attention. Ever kept your "significant other" waiting just 20 minutes?
At a rough guess, she’ll be somewhere on the scale between homicidal
and genocidal. Not a good start to a relationship. Next night, it’s the
same, she’s been waiting 80 days as well. And so on. And don’t even
think about limiting your favors to a select few. Maybe "Hell hath no fury like a woman scorned",
but don’t imagine it’ll be any better in Heaven either if you miss some
of them out. You could of course declare that all relationships will be
purely platonic, all that you want is company and conversation. Now all
you need to do is find the one who’s equally interested in taking motor
bikes to bits. Or the one who’ll enjoy watching Sumo Wrestling with
you. Or the one who’s any good at Darts."

RTR.