Gay people don't wear their sexuality on their sleeves; so there's no way to tell whether a stranger identifies as LGBTQ unless they're wearing a rainbow T-shirt -- and even then, some people just like rainbows. So, if you're looking specifically for gay friends, you could have some trouble identifying them. Even if you're gay yourself, you might find yourself wondering where all the gay people are. But if you go to the right places and make the right overtures, you'll be able to meet plenty of gay people.
Go to a gay club or bar. If you're under 21 or live in an very rural area, this may not work for you. But in many cities and towns, gay bars are hotspots of the queer community. Walk in, get a drink, and strike up a conversation with someone. Mention that you're there to make friends. Most queer communities are very welcoming of new people -- after all, most gay people have faced ostracism at some point. Most people will be more than happy to make you feel welcome.
Volunteer with a gay-friendly organization. There are many foundations, groups and organizations dedicated to civil rights for gay and transgendered people. Giving some time to one of them will open up a whole world of possible friendships. What's more, working on the same issue or project will give you plenty of conversation fodder, if you're bad at small talk.
Look for signs. You may not have to go out of your way to make gay friends -- they may be right in front of you. It impossible to know whether someone's gay or queer unless you ask them, and yes, it is rude to do that out of the blue. But sometimes, there are hints that a person might be gay -- for instance, if your coworker wears a ring but talks about having a partner instead of a husband or wife, he or she might be gay. Bring up gay news or issues in conversation and see how people react.
Get on the Internet. If you have a connection, you can make gay friends. Craigslist has a platonic personals section, and there are many other sites out there that help people make friends. This may be your best option, if you're far from a big city or have just moved to a new place. Post on one of these sites and say you sincerely want to make some friends -- someone's bound to respond, even if you can't meet them in person.
Don't treat gay friends as accessories. Many people, especially straight people, want gay friends because of the novelty it brings. Gay friends are just like any other friends -- they can be boring or interesting, quiet or outgoing. Don't expect your gay friend to go on shopping trips or do other stereotypically gay things with you.