I spotted her just as I was leaving the party. For a second, I felt confused. She looked familiar, but I didn't think we'd met. Her face was pretty in an old-fashioned way — soft eyes, pale skin, light dusting of freckles. I felt like I was remembering her from an old movie. She could have played a pioneer, bravely slinging a rifle over a calico frock as she marched across the plains. She would have been equally convincing in a '40s detective caper, making smart-alecky remarks to Cary Grant while she sipped bourbon from a flask.

"Excuse me," I said. "I think I know you."

"Yes," she said. "You seem familiar."

The explanation was more prosaic. Caitlin and I lived in the same neighborhood. We'd seen each other around, had taken the same yoga class. A few coincidences gave me that tingly feeling of destiny. She had come heartbreakingly close to purchasing the apartment just above mine. We had a friend in common, David. And we had occupied the same studio at an artists' colony, which was why the name on her tag struck a chord. She had the workspace two months before I did and had, as per the colony's tradition, written her name on the doorway. I had spent many idle moments reading the names and remembered Caitlin's in thick blocky letters across the portal.

We were also both writing novels. (Though this isn't much of a coincidence if you live in New York City, where it seems just about everyone — your mother, your podiatrist, the guy who makes sandwiches at the deli — is vigilantly pecking away at some opus.) We talked about our books, and the work we did to support ourselves. I was a freelance writer who paid rent by writing internet quizzes that helped the intrepid web surfer determine their fitness personality or their marriage-mindedness. She was a television editor charged with weaving reassuring narratives about couples having their first child. We lamented that our least-challenging work was also the most lucrative. "Mediocrity really pays," she said, archly.

That's when I fell for her.

Although I am straight, I am constantly falling in love with women. I slip them my business card at parties, or shyly suggest a cup of coffee after yoga class. I strategize about the best ways to reel them in: dinner party? Invitation to a play? Some pretext about work? I swoon when I get their emails and chatter endlessly about them to the men I date. When it works out — when my new pal and I emerge from an hour-and-a-half of feverish conversation and realize we're just getting started — I'm over the moon.

I fall in love with men too, of course. But because my relationships with them involve sex, or at least sexual attraction, they're murkier and more anxiety-producing. This tension has a delicious side too, obviously, but it's in the uncluttered love of the platonic friendship that I feel most at home. The heterosexual date has a quasi-mandatory feeling to it. Sure, it's great to drink beer at an outdoor café with a good-looking guy, but there's always an underlying agenda. The buzz, the stars and the conversation may be wonderful, but they're a means to an end.

By contrast, time spent with close friends feels giddy and breezy. We help our pals in times of need — we pick them up after surgery, paint the trim on their apartments, and honor our solemn duty to yelp in outrage upon hearing about their impossible bosses or lazy-ass boyfriends. But mostly, friendships are about pleasure.

Of course, the downside to such a tetherless relationship is that you lose people, or at least lose parts of them. One of the reasons I so ardently pursued Caitlin is that Karen had just moved to Seattle. Nancy was in London, Mary in Kansas, Meghan in L.A. Helene had just had her second child, Kristin had just moved in with her boyfriend, and Daphne had just fallen in love. I still adore these women, and through the twin miracles of cheap long-distance and airfare, they're still great friends. But when I chatted by the coat rack with Caitlin for half an hour, as other guests squeezed past us to collect their leather jackets and ponchos, I knew something important was happening, and that I had to get it right.

The hardest part of making a new friend is admitting that that's what you're doing. There's something vaguely shameful about shopping for friends as an adult. You're supposed to already have an established group of old college pals and officemates. You're supposed to be busy — that is, successful. Actively seeking new friends seems a pursuit for the lonely and undesirable.

Which is why it requires a bit of seduction. You want to show interest but not appear too needy. As with sexual relationships, this can be a tricky balance. I actually almost blew it several years ago, when I first met Meghan. Once again, I met her just as I was about to leave a party. The friends I came with had called a cab, which I'd agreed to share. Then someone introduced me to Meghan, and I correctly guessed that she was the author of an essay I'd recently read and adored. That Sunday morning, after I pronounced Meghan's essay brilliant, my then-boyfriend told me he knew her, that I'd like her. I immediately demanded an introduction.

Now here she was. I complimented her essay, and from there we were onto a string of seemingly unrelated and yet intertwined topics, finally landing on a recent fashion-magazine article where women revealed how many men they'd had sex with, and how they felt about it.

"Was that put out by the Christian Coalition?" she said.

"I know! Where was the woman who said, 'I had tons of sex, and it was really fun'?"

"Or: 'I was a total prude in college. What a waste!'"

Then my friend Paul tapped me on the shoulder.

"The cab's here," he said.

Meghan and I looked at each other like star-crossed lovers. "I promised these guys I'd leave with them," I said, lamely.

"I wish I had met you sooner." "Me too," I said. As if I couldn't have just stayed, taken the subway home or shelled out twenty bucks for my own damn cab. It was a silly and vain moment. I didn't want Meghan to know how much her potential friendship meant to me, and so I risked never having it at all. Fortunately, my boyfriend delivered on his promise. He had a party. Meghan came, and then made me the happiest girl in the world by saying she'd read and liked an essay that I'd written, that we should have lunch.

With Caitlin, the whole getting-a-ride-home issue worked in my favor. I came to that party with my friend Helene, who also lived in our neighborhood and had a car. We offered Caitlin a ride, and then out for a drink. The evening ended with email addresses scrawled on cocktail napkins and promises to do it again sometime. A week later, I popped her a quick note, asking if she felt like getting a beer. She said she did, but work was crazy right now. So that was that. For several weeks, I didn't hear from her, but then she wrote to say that she had bumped into David, that the three of us should make a plan. This proved to be one of those exhausting back-and-forths — schedulings and reschedulings that went on for weeks. After an eleventh-hour cancellation by David, Caitlin and I met on our own. We talked about the crazy new reality show she was editing, the sweet old dog I'd just adopted, and how much we hated George W. Bush. It was fun, as it was a few weeks later when we finally met up with David, but something wasn't quite happening. We were still two women having a drink in the neighborhood. We needed to cross that line, to become real friends.

I can't remember the exact moment it happened, and neither can Caitlin. Maybe it was just the cumulative effect of X number of drinks, brunches and dinner parties. All I know is that at one point, we became the kind of friends who talked on the phone every day, and RSVP'd for two on invitations without consulting the other. She became someone who, two days before election weekend, agreed to join me on a last-minute bus trip to Ohio.

We spent election eve at Kerry's last rally in Cleveland. Our group was heady and confident after a day of door-to-door campaigning. During the primaries and well into the campaign, I was lukewarm about Kerry, but that night I gleefully drank the Kool-Aid. While Bruce Springsteen played, Caitlin and I sat on the shoulders of two fellow canvassers, waving a rainbow "We the People Say No to the Bush Agenda" flag. Looking back on that moment, our confidence seems foolhardy. But that night, as people in the crowd passed around homemade brownies and sang "No Retreat, No Surrender," we set aside our usual New York detachment. We genuinely felt that we were part of history.

Caitlin turned to me with a bemused smile. "Did you ever imagine this would be so much fun?"

I had a pretty good idea.