Either say nothing, or “What do you want ?” probably. I don’t think I could bring myself to give him any title of respect. I’d try to be polite enough not to call him “RatPope” or “Pope Palpatine” to his face. Probably.
How about Benny?
What’s up Benny? You still sittin’ on that big ole stack of pr0n?
Meeting the current Pope?"
I guess a few years back “Zum Befehl, Obergruppenfuehrer Ratzinger” would have sufficed.
I’ll call him Your Holiness if he calls me Princess Anna Louisa Berthe Franchesca Banana Bana Fo Fesca the Third. But if he makes with the holy wine he can call me Dot.
Atheist here. I’d feel uncomfortable calling him “Your Holiness” because it sounds so silly. I also didn’t use the “Father” title when my wife and I were going through premarital counseling at her Catholic church.
I call him Pope Ratzinger when discussing him with my wife. I’d probably call him ‘sir’ or perhaps Mr. Ratzinger. I did the same with the priests.
Gawd, I’m a sucker for an Animaniacs Quote. 
Big hats?
I could never call another man “Your Holiness”, be he a Pope or Lama, Dalai or otherwise, simply because I don’t believe anyone is holy, and find the idea of playing along with such a conception, and giving reverence according to same, repugnant. That said, if I were ever to have a speaking encounter with the Pope, I’d certainly call him “Sir”, because I was raised with manners and tend to address all older gentlemen that way. For what it’s worth, I grew up in a Protestant church of the hellfire-and-lamb’s-blood variety; now I’m a thorough-going heathen with strong Thelemic inclinations.
I’d ask beforehand for acceptable ways to address him, and pick one. If I’ve already decided to treat him with respect, I don’t have a problem with “your holiness”. This from a hard atheist with severe hostility to religion.
I’m an atheist, but this is pretty much exactly how I feel about it.
I’d call him sir. I would try very hard not to call him Your Holiness. I’ve had enough of calling mortal men holy, with my upbringing, what with Sai Baba and Shirdi Sai Baba and all the other sages and [del]idiots[/del] brahmins in India.
I wouldn’t be rude to him but that’s more because of his age, and I was raised to at least be polite to old people.
In the end, however, it’s just words. I would love to sit him down and ask him, face-to-face, about some of his policies and what he really thinks they are doing in this world and if he has any concept how real people live. Since there’s no possibility of that, I’d just be polite.
But how would I meet him? No way in hell am I going to the vatican.
“Miss Manners signs letters to her business correspondents, ‘Very truly yours,’ and so far has not been required to give herself to any of them.”
“Your Holiness.” It’s a polite noise, not meant to be taken literally.
I don’t think I could do “Your Holiness.” So I’d have to go with Sir. Then I’ll bring up how much I like Regensburg.
I have no problem with Sister and Brother for nuns or monks, but Father? I don’t care for that one either. Picky, picky.
Current Atheist/Agnostic, former Catholic.
I’d use “Your Holiness.” Because it’s polite. After all, I’d have made an effort to meet him. He won’t be hanging out at the bus stop or my local bar.
Not that I’d be likely to request an audience.
I wouldn’t cross the street to meet Bush, either. But I doubt I’d be polite to him. Hey, I’m a Texan.
Ok, just one or three more. If I was really baked, which I haven’t been in years.
“Your Popiness”
“Your Popitude”
or
“Your Popitudinousness”
Then I’d really mess up, call him Papa John and ask for a pizza.
I sort of figure there isn’t any reason for someone like me to meet the Pope, or the President, or whatever and not treat them (or at least the office they hold) with respect.
Miss Manners says something about referring to judges as “The Honorable” - she says that even if they are in prison for fraud, they are still “The Honorable” - you just get to take great joy in the irony.
Speaking as an Atheist who has never been Catholic, if somebody forced me to meet the pope or George Bush for some reason, I would feel compelled to let them know how much I abhor everything they stand for. And one thing I would do is refuse to refer to them by any sort of title. Besides, I don’t think the pope is holy and I don’t think Bush deserves to be president. If I did not convey to them my true feelings about them, I would feel pretty dishonest and crummy afterward.
If I am meeting the pope, it is time to up my meds man
Hey guys, if you read the source, it seems like this was in answer to one question, not a formal greeting. I see nothing which sez GWB did not formally address the Pope as “Your Holiness” when they first met.
http://news.yahoo.com/s/afp/20070609/od_afp/vaticanpopebushgaffe