It’s something a lot of writers try. Not everyone can do it, especially on a consistent basis that it takes for a novel.
We discussed it at my writer’s group today. How difficult it is to identify with the other gender convincingly. I love the candor of the group – they’ll tell you when you stray and expect you to do the same.
Like when male characters, otherwise ordinary, start spouting off long bits of dialogue. Or when female characters seem oblivious to the surroundings. Just another thing to keep in mind.
Why couldn’t one thing be easy? Oh, yeah, it’s because we’re writing.
Ransom Noble 
Interesting topic. I guess I’m on the spectrum of writers that do write the other gender. But I’m sure it’s not quite the same since I write gay male.
I find that, for the most part, I can slip into writing a female with a fair amount of ease; but then again, I can relate, and to a certian amount, identify with the character, so perhaps being gay gives me a leg up. 🙂
One of my favorite published stories was written from a female’s perspective. It was fun (dark, but fun). I haven’t tried it in book length yet. Otherwise I usually keep to my own gender. (in fact my stories seem to be male dominated.)