I found this post through google. I laughed like hell at the original question, assuming the reply to it would set the record straight, but wow. Really, wow.
I'm amazed that someone actually still believes that homosexuality (or more than likely, most sexuality-related deviation from the more normative heterosexuality), is a mental disease and can be cured by science or religion. I do hope you're aware that if you were to make a list of all notable humans that have lived over the past few hundred years, then filtered out all those with average or below-average intelligence (leaving only highly intelligent people), then you'd find that religion within that group of people, is a minority.

I myself am gay, and I have many gay friends. Some of them are even christian, because they believe that (like it says in the bible) God loves everyone. I also have a higher-than-average intelligence, and am working to get into university (With psychology and several computing qualifications). I'm also openly gay to pretty much everyone (including one of my christian friends). Do you know how many people have any kind of problem with it? Yeah. Zero. Do you know how many people I've hit on? Again, zero. Not every gay man or woman wants to hit on you or have sex with you, and if you genuinely believe that they do, then I'd suggest you ask someone to slap some sense into you.
I know that when it comes to homophobia or general hatred of gays, the reason for this is in most cases religion and/or ignorance. You, Kip, fall into this category. However, there is a line between ignorance, and pure, concentrated, blind stupidity. You seem to think that homosexuality is some kind of biological or psychological disease, which scientists will at some time be able to cure. Wow, will they be able to cure people with psoriasis, schizophrenia or dementia? Because they've been trying to. For years and years. And guess what? Those three diseases are listed as incurable.
Your beliefs, in terms of homosexuality, give new visitors to your site the impression that you believe yourself to be living in the dark ages. You know, those old times when people were punished for unbelievably stupid crimes by hanging, dismemberment, and other horrendously violent methods. Oh yeah, they also believed in witches, and punished them by burning them to death.
It's either the dark ages, or the 1800s, wherein homosexuality was, again, believed to be a disease. During that time people didn't believe in things like basic hygiene, either. That lead to things like bubonic plague (Black Death, or simply "The Plague").
If you look at the general consensus of people living today, most people will say they have absolutely no problems with gays. On that same note, rather alot of people will also say they're atheist, or otherwise not christian.
I'm betting that if you read this post, and reply to it, you'll pull the standard "GOD SAYS IT'S WRONG IT MUST BE TRUE BECAUSE I MISINTERPRETED THE BIBLE TO FURTHER MY OWN AGENDA LIKE MOST LIVING CHRISTIANS TODAY." and/or "IF WE ALLOW GAYS TO BE THEMSELVES AND TOLERATE THEM AND STUFF, SOON BEASTOPHILES WILL WANT EQUALITY AND STUFF BECAUSE SOMEHOW THAT SEEMS LIKE LOGICAL PROGRESSION TO ME. ALSO PLEASE IGNORE THE FACT THAT I HAVE MORE OR LESS NO LOGIC OR REASONING SKILLS, AND BLINDLY FOLLOW THE WORD OF GOD WITHOUT QUESTION. ALSO YOU'RE GOING TO HELL."
I actually wrote more in this comment than I had meant to. Oh well, words that are likely to be wasted on you anyway. I'll say this: I'm not forcibly trying to change your beliefs, nor am I saying you shouldn't be christian. What I'm saying is, you should take a step back, look at the world as it is today, then examine and question your beliefs. I've read the bible. I know perfectly fine what it says, so I know for a fact that it says people shouldn't blindly follow the word of God. They should question it, using logic and reasoning, and believe what they think is true, for themselves. It also never explicitly stated that God hates gays. Yes, it says that things like sodomy or sexual actions between members of the same gender are wrong, but not once does it state, anywhere, that gay men should be judged and hated. It also doesn't mention anything about it being a disease.
I don't expect any logical and valid response that makes any kind of real sense, which is why I supplied a fake name, email address and a website I don't call my own (to prevent people from emailing me with short, pointless "YOU ARE LIVING IN SIN" emails). I'm merely posting this because I truthfully cannot believe that someone with the intelligence to know where the power button on a computer is, and knows how to run a website to any degree at all, can have such unbelievably draconian views on homosexuality. Even my parents, who are christian and don't really tolerate gays, don't believe it's a disease. They believe that it's wrong, yeah, but they have realistic views on it.
You, as someone who runs a website for providing advice to people who need it, owe it to your readers to provide valid responses that don't rely entirely on the person asking the question, to be religious. Many people aren't religious (myself and most of my friends are atheist – even though I've done extensive research into religion), but still seek advice from websites like this. So the next time someone emails you asking for advice on something, think before you respond. Write back, but give a response that can apply to more than just the christian population.
Advice to the original poster of the question, Closet Case Cautious, you shouldn't think any different of your friend. If someone is a true friend, they stick by them through almost anything. My best friend recently found out about me. He was surprised at first, and couldn't entirely believe it, but he accepted it and moved on (after asking a few questions first). If you reject your best friend, someone you say you've stuck by for years and years, investing most of your time in, just because he's gay, then you don't have the right to say he's your best friend. Rejecting him and ending a friendship you say has lasted for a large majority of your lifetimes, would be a colossal mistake which you'll likely regret in months or years to come. Not only that, it'll make your best friend feel worse about himself. I've seen cases wherein post-coming out rejection from someone highly regarded within a gay person's life, leads to cases of severe depression, anxiety, and other stress-related mental issues. In some cases, this can even lead to suicide if the rejection and loss of a best friend is too great. In summary, accept him, and try to move on. Make your views on homosexuality known to him, if you have any issues with it. Make sure he knows you're straight, if you think he doesn't already know this. But don't reject him. That's what is in most cases referred to as being "a complete asshole". Rejecting him would likely turn other friends against you. I've seen it happen before, and it'll probably happen again.
The length of this post, was purely accidental. I apologise for the length of it, but give it a read if you can.