h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I think I like your kind of party except for the bit about photos. Have you ever heard of the term "blackmail" ?

To avoid blackmail, make sure that several ppl gather at one time to view a pack of photos. Therefore, the pictures will be passed around a group. When anything particularly incriminating comes by, conceal it about your person. This can be done by creating a backlogue and passing on several (minus the bad pic) to teh next person, creating a diversion, waiting until someone else has the groups attention, or having an accomplice. The best clothing to hide the photo is a windcheater with the ribbing turned up. This creates a nice little 'cup' which is dificult for the pic to fall from if you don't make any erratic movements. Also, if any one gets suspicious and asks you to lift up your jumper, the 'cup' will remain if you grab it correctly and the photo won't fall.
Ppl say goodbye and leave none the wiser!!

Tried and tested method!!!

Ideally, I'd suggest that a doctor should be present to treat the inevitable cases of alcoholic poisoning and to dish out painkillers and morning-after contraceptive pills the next day.
Having a psychiatrist or counsellor there is also a good idea, so that there's someone to help the person who, around 1am, will be sitting on the stairs telling anyone who'll listen that they want to die because (fill in name) doesn't love them.
Trouble is that the only medics and shrinks I know would be likely to get too wasted themselves to be much help. Ah well.

Make sure you're pushing alcoholic drinks continually into the palms of anyone there who looks uneasy or reserved. It can only help the life and soul of the party.

PRAY that the toilet doesn't break and perform constant checks. Replace toilet rolls too. You know what they're going to wipe their butts on if the roll is spent.

Gimmicks to get people in the mood are fine. To ensure a good party, you're going to have to make a boob of yourself at some point. Just make sure that everyone is in the party's groove before you do.

For partythrower's that think that they can get away with throwing a party in your parent's home:
Put anything VAGUELY breakable and put it in a reserved room and lock the door. Think, "What would happen to this if I dropped it" and "What would it take to stain this", for they are good starting points.
Steamclean the carpets before they get back. Otherwise they'll just know.
Pay off the neighbours.
Keep it small. Yeah right. Well try to anyway.

Alternative method to avoid blackmail - make sure you're the one taking the pictures and never let the camera out of your sight. Works for me.

And for ultimate embarassment, post all the really good photos on a web page! (Sorry Phil)

and try to keep one person at a time in the toilet, especially if it designed to be used by one person at a time.

Now I like the idea of throwing all the party pics up onto a webpage. Why blackmail if the whole world can see the photos anyway? Of course, this may make some people tense about having their picture taken at your parties so it may be best to invest in concealed camera equipment. Combine this with live partycams and locating all the cameras could become the main undercurrent of activity at the party.

Don't forget, though, that seeing home videos or photos of other people's parties is second only in mind numbing dullness to seeing other people's holiday videos/photos. Therefore they should only be put on websites where people won't trip over them accidentally.
And anyway, pictures of people snorting flaming blue cocktails NEVER come out as well as you hope.