I guess most of the posters here missed the MythBusters program. They covered the last poster's question about what would happen. They talked to a guy who knows about these 'vacuum' toilets and said it would not be too much of a problem since the vacuum only last short time, like three seconds, I think. Adam, one of the guys on the MythBusters, sat on the toilet simulator without the seat cover with their homemade vacuum system (they did not have it designed for short time vacuum) and it's not something you'd want to experience.
Another thing they covered was that there is some kind of relief valve in the design so this would not cause one to get stuck during the short vacuum time.
The MythBuster guys did a pretty good job of going over this one to dispell any scare about getting stuck on the toilet while flying.

HJ

8psi? That's something like 250-300lbs of force, if my math is right. I'm not sure I'd want to even try that to see what it's like....

I have! I have! :p I hit the flush pad/button by accident and was terrified as soon as I realized what had happened. I had heard the rumors of being stuck to the seat and unfortunately this was BEFORE Mythbusters did the show on it. I felt nothing other than a breeze, no suction so to speak. I have what could be considered a generous backside (although not TOO generous mind you) so I think I had adequate uhhhh... material to form a seal for those of you that might be curious if that was a consideration.

-A

Someone give this man a medal !! ^ ^ :D :D

As the Mythbusters showed, there's an air gap under the cowling so you can't get an airtight seal without diassembling the toilet.

Because of the suction, I suspect a vacuum toilet has less of an aeresol spray than a regular toilet.

Didn't someone get stuck on a toilet on an SAA flight last year? I vagely remember reading something about that...

How do I buy one of these for my home?