Nowadays its very easy to start your own social networking websites. Thanks to many free script available in the market. You can start your own social networking website and can challenge facebook/orkut/myspace/hi5 etc.
oh !!! Brother free is always free. It can be refuse any time. And another thing is that it is herder impossible to come closer to faceboook, orkut, myspace, hi5 etc. But there is a quote "NOTHING IS IMPOSSIBLE" You can do anything if you try to this.
Yes,it's so easy that even a 2nd or 3rd year engineering student takes social networking site as his semester end project. But the thing is how many facilities are there for user & most important, features should not be copied from famous networking sites. You have to provide something different then conventional features. Today FB & many other sites are providing so much features that you have to be genius or think powerful to make your site popular & get attention of users.
Scripts are available but one cannot get registered users without some innovation. "Innovation distinguishes between a leader and a follower" - Steve Jobs
So? In the end it is the users (how many of them do you have) that counts. In one year, most, if not all of those domains will be parked or back for sale.
I have know some social networking sites but most of them are imitating the style of Facebook and/or Twitter.