Even if you don't plan on entering very often, it is well worth downloading the SL viewer since an increasing number of links will be pointing to "SLurls" locations you will not be able to see without access to the sub-system on your computer.
In the near future I will be publishing one of these here myself. It will take you directly to a 3D hub where you will be able to access everything of mine through this new interface.
Interaction on Facebook, MySpace and other social networking sites is mainly limited to text, with the ability for users to add photos and video. But in a virtual world, people are represented by avatars: computer-generated figures which can look uncannily like ourselves -- if we choose.