Well, this is an american custom and I’m french, so clue me in!
I guess it depends on whom you are kissing. Your mom? Your coworker? A casual acquaintance? No. The person you are dating? Yes.
Aren’t the French supposed to be the kissing experts?
What’s the big deal with “tongue” anyway?
I’m not so sure about this being “yes”. If you’re alone (and it’s OK with both of you), yes, but if you bring your date to the office or family holiday party, and start trading tongues under the mistletoe, I’d say you’re not being polite to the rest of the people.
Huh? I cannot kiss my mom with my tongue?
Well, Uniball, your mom always likes it when I slip her some tongue, so why don’t you try it.
And yes, Zenbeam has a point about the office party. No tongue at the office! Not even with your mom.
Hehehehe, this just cracked me up magdalene. I think it should be on one of those signs that HR departments put up around the workplace.
“O bon Dieu! les langues des hommes sont pleines de tromperies.”
“What says she, fair one? that the tongues of men are full of deceits?”
“Oui, dat de tongues of de mans is be full of deceits: dat is de princess.”
–King Henry V, Act V, Scene ii
If you’re algore you can use tongue anywhere, especially the Democratic Convention.
You should use your tongue but it really depends which set of lips you are kissing.
Well I can just see it having to kiss grandma and getting the tonge.
Uniball, how can you be French and not know about Frenching?
Like said, it depends on whom and the circumstances. If it’s a complete stranger, she’d better be really cute (and not have a boyfriend standing nearby), and you’d better be pretty drunk. 
If it is your current girlfriend or wife, tongue is probably okay, unless it’s an office party or other formalized/professional environment. An after hours office party, tongue okay. An at work luncheon, skip the tongue.
As to kissing your mom, well maybe the French can pull off Frenching their mother, but the rest of us get an icky feeling. Tongue is reserved for a romantic interaction, not casual exchange.
magdelene, if you’ll come over here, I’d be glad to demonstrate what the big deal is. 
Of course handy makes an excellent point. Be wary, however, of doing that at office parties, too.
In China, chinese food is simply called… “food”!
Same logic goes to english muffins, mexican burritos and, yes, french kiss.
Ugh. I think we’ve established the General Questions answer to this, such as it is.
Closing this thread.