I think Jerry and Elaine were pretty much the perfect guy/girl friends. Even when they decided to have sex, they made "rules" for it so as not to damage their friendship.

I can't really say for sure if a woman and man could be genuine friends without any sexual feelings for each other, but I suppose it's possible.

My best guy friend is my cousin; we're the same age, we live next door to each other, and we go to the same school, so we're very close. I don't know if it's from growing up with him, his brother, and my brother, but I've never been a very "girly" girl. I'm not saying I'm not into any kind of "chick" things (y'all have heard me gush about You've Got Mail and Sleepless in Seattle...and all of my favorite baseball players...*ahem*.. ), but most all of my girl friends are girlier than me. While they're there for me all the time as friends, and I know I can rely on them and trust them, I've found that I can have a lot of fun with guys, just as friends, as well. There are only a few girls that truly care about baseball, roller coasters, and some of the things I like, so I find myself enjoying the friendship of guys more so in those matters. I have had feelings for some of my guys friends, but I appreciate the friendship that we have. I would hope I'm not being "selfish" in any of these relationships...

Sorry for being a movie nerd, or...something, but this reminds me of a quote from You've Got Mail (Imagine that, huh?):

"You're taking it to the next level. I always do that. I always take a relationship to the next level, and if it works okay I take it to the next level after that, until I can finally get to the level where it becomes absolutely necessary for me to leave."

So...I guess if you're a "friend" with someone who likes to always "take it to the next level," you might have trouble being "just friends," but I don't think it's impossible for a guy and girl to be genuine friends without deeper feelings.