I have seen a lot of my friends go through this dilemma. They are former forum/blog people with decent experience. Now they want to start a project and want to try something that can work like or take on Facebook. I don't know why they are obessed with competing Facebook. But according to them, that is only the way to survive. They do not think that a conventional blog or forum software is enough to take back their investment.
What is your choice for the next project ?