Social websites give you an Internet presence and demonstrate that you are technically savvy, an important quality when you are changing careers in mid-career and beyond. Wikipedia lists 128 social networking websites globally and includes the disclaimer that the list is "limited to some notable, well known sites". The ones I will review are among the largest or those most pertinent to the job search process.

Social networking sites give you a place to let people know about you on the web. One of the challenges for the person in mid-career and beyond is providing the indisputable proof that they understand and utilize today's technology. These sites can go a long way to demonstrating that. This is also a good way to be in touch with your network and build a more extensive one during your job search.

First, let's eliminate those social networking sites that aren't of much use in a job search -- the websites that are purely social or special interest. Such sites include ones like Buzznet.com for people interested in music and pop culture (10,000,000) and CafeMom.com for mothers and mothers-to-be (1,250,000).

General interest social networking sites, on the other hand, provide both social and business contacts and communications. Most popular among them is MySpace.com with 403,000,000 registered users followed by Facebook.com with 115,000,000. These are places to find former friends and colleagues and communicate with your own network about the progress of your job search campaign.

There are some special interest sites that could be used for business as well. If you are a photographer you might want to have a presence on Flickr.com while professionals with an African American background might get some job search mileage by being on BlackPlanet.com.

Purely business "social" networking sites include LinkedIn.com with 25,000,000 users and Plaxo.com with 15,000,000. Both are targeted to the professional and are heavily used within the business community. They enable each user to post a professional profile and a photo. In addition, you can invite your network of contacts to join you so you can keep up to date on what each other are doing and make business and job referrals. LinkedIn includes a job board and Plaxo sends out regular updates of member activity to the people they are connected to.

Meetup.com, while technically a social networking site, is most valuable for the list of local meeting it sends out regularly. Beware, however, you may have to search through a lot of irrelevant meetings to find the ones you are interested in attending as part of your job search campaign. Reunion.com is helpful for finding contact information for people you went to school or college with.

As the numbers and size of social networking sites expand on a daily (if not hourly) basis, they are here to stay as part of the job search process.