linkedin

linkedin seems like a good site for professionals. You can post resumes or advertise your services. You can join groups of professionals that are in the same industry as you. The only downside is to fully use all the functions of the site you have to pay a monthly fee.

myspace

myspace started the social networking scene. They are still one of the biggest social networking sites on the internet. Unfortantly unless you are good with html it is hard to customize your page. I still log in once in a while to check the messages from people who have not moved on to FB.

face book

I feel face book is the ultimate in social networking. It is easy to use and it's free. You can keep track of friends. Send private messages. Control privacy settings on all friends and post all events. It is the most user friendly to use. I use it all the time.