What is real friendship?

There are many types of friendships, but what does it mean to be a friend to someone?
To be a genuine friend to someone, you shouldn't be afraid to express your own opinion, especially when giving advice. Too many people now a days just agree with what their friends think because it's just the easiest way to get along, but are you really being a good friend by doing so?
A real friend is always honest, and will tell you if they believe something isn't right. Even with the silly things by saying what you're wearing is ridiculous, but in the nicest way possible, to the more serious things where they think your idea of going about a situation is wrong. Good friends will honestly guide you every step of the way, yet won't judge you for mistakes you make.
One example that springs to mind is when a friend falls out with someone, how many of you jump on the bandwagon, especially when you're with that friend, bitching about that person when you don't mean it deep down, you do it just for the sake of it? It's such a petty reason but it really goes to bite you in the ass when the person finds out you've been two faced.
A time when friendships are tested is when friends in your group fall out and your reactions to it. To be a good friend you have to stick to your own opinions. If you just agree with what your friend says to you, then to other people agree with their conflicting ideas, both sides will feel betrayed by you and feel you've lied. Too many people do it. Good friends would point out where the problem is, and try and resolve it. Even if it means admitting to them they're in the wrong.. especially when you know they won't like it.

There's more to friendship than spending X amount of time with them and just listening to them agreeing with what they think and how they feel. Would you want your friends to just agree with what you say even though it's wrong? The whole point in having friends to support you is that they make the situation better, or at least easier for you, but how is that meant to happen if they're agreeing to the wrong things, or saying the wrong things?
No one seems to have any real opinions anymore, we know everyone does but they don't voice it to the right people. We go behind each others backs and express those views to other friends who have nothing to do with the situation while we're meant to be telling our friends. Sometimes conflicting ideas does cause arguments, but who goes through life without arguing huh? Surely it's better than the arguments that follow your friend finding out you've been two-faced or a friend of yours has been two faced. There's taking both sides into account, and there's just being plain bitchy.

Real friends don't judge you on how you go about things and how you feel about certain situations, they accept, repect them and take them into account when they've asked for advice etc. Friendships are seeing more and more fake to me, people pretending to agree to something because it's the easiest way to get along. Today a lot of people are really two-faced and there really isn't any need for it. If you feel the need to be two faced, then maybe you should be re-considering who your friends are.

This is just one part of what it means to be a real friend, but it's a part that I feel is really lacking today, when I look around the people I know... What do you guys think?