This about sums it up.

That's what I appreciate about the men in my life -- their masculinity. Similarly, I doubt I fill a “one of the guys” role to any of them. A male friend is not a slightly hairier substitute girlfriend. If I want to get my nails done, I’ll call a lady. If I want to talk about motherhood, I’ll call another mom. My guy friends, on the other hand, will hang out for an entire evening and never once mention anything to do with feelings. If one of them forwards me an e-mail, there’s an 85 percent probability it involves "Star Wars" and zero chance it contains a quote from Maya Angelou. If a man I'm not sleeping with tells me I'm beautiful, I believe him. I have had guy friends gallantly toss me over a shoulder and carry me through big puddles. They have, when I've been blue, asked if I needed somebody’s ass kicked. My guy friends have never asked to split an appetizer because they were really trying to stay in the Zone, nor looked at me like I was a war criminal for ordering dessert. And while I’m no fan of sweeping gender generalizations, I will note anecdotally that if you’re the sort of woman who finds fart humor hilarious, you will never lack for male companionship.

-Salon article on, "Guy Friends Rule" - Mary Elizabeth Williams.