With all these social networking sites readily available to everyone who has internet access, it really is a good thing to tell which one is worth joining and which one is not. Everyone seems to be in Twitter and Facebook nowadays. There are also social networking sites like free dating online at Zyngle.com that is starting to make a name for itself.
The key really is to have a measure of control over your online accounts through tweaking your privacy settings. You can never be too sure about who is viewing your profile. Be vigilant as you socialize online.