Well, I'd like to step in play devil's advocate here...
What *I* find amusing is how quick people are to blame a piece of technology for their own failings.
If your friends are forgetting to invite you to things because you're not on facebook, or your friends are clicking 'like' on your facebook page because they can'tb be bothered talking to you, the problem is not facebook. The problem is your friends.
Social networking sites, such as facebook, give us quick and easy ways to do a great multitude of things that we enjoy doing, including interacting with our friends. They don't have to REPLACE all those things.
Just because it's there it doesnt mean you have to use it. There are escalators at the train station, but you can always use the stairs too.
In other words, a 'Like' button (like anything really) should be used in moderation. Sometimes a long response is NOT necessary. Before the 'Like' button even existed, people used to say "I like this pic!' and leave it at that.
The mere existence of a 'Like' button does not take away anyone's ability to post thoughtful repsones. Only your own attitude towards the 'Like' button will do that.
So, Rumenist, I agree with you on your point that reducing human interaction down, distancing ourselves from our friends etc, is not a good thing. However, I don't agree that facebook, or any piece of technology, ought to cop the blame. Humans are responsible for what happens to human relationships, behaviour and social lives. Not computers.