Plaxo/LinkedIn vs Myspace/Facebook

Plaxo and linkedin are some very good social networking sites and I can see the similarities when it comes to facebook and myspace. The biggest differences I see are the kind of people they draw. I find that plaxo and linkedin cam attract an older and more professional demographic. Possibly something that you would like to give yor coworker. While faebook and myspace are more geared to the college age ppl and true friends. Information shared can be quite similar while plaxo and linkedin get a little more personal and almost have a feel of a resume or portfolio with interaction.