Just want to reply in order to correct this post.
1. There is internet in the Philippines. We're not the number 1 solution for outsourcing if we don't have internet. Sure, you'd have to make do with 1 to 3 mbps of speed. But it's unfair to say that we don't have internet.
2. You can easily find a 10 room mansion to rent, but not for $500. You're looking at about $2500 for something that huge. You just have to know where to look. You'll probably have to settle in a first-class municipality, not Manila.
3. We do have air conditioning, not just hotels. In fact, my air conditioning is running right now.
I'd have to agree that it can get hot and humid. But the OP did say that he's planning to come here on December. Weather's good from December to February.
Just like in any other country, there are bad and there are good areas in the Philippines. I'm sorry to hear that some of the posters here have had bad experiences. But maybe they stayed in bad parts of the country. Take Manila (the capital) for example. I'm not a big fan of it. It's too chaotic even for a Filipino like me. This is why I moved out of there and went back home to the province (a first-class municipality with all the conveniences of modern cities but without the chaos).
Now, you have to remember that you're the one visiting. This means that you're the one who has to adjust to our culture. Generally speaking, Filipinos are nice and hospitable. But if you're rude and you act all-mighty, you can't expect the same treatment. Familiarize yourself with the people and the cultures and you'll have an awesome time.