After working with livetext for the last 2 years I do not believe there is any better program available for creating a teaching portfolio. Now that I have re-created my portfolio with Google sites, I believe it has some advantages because of the web-based, public access to my information. With livetext, a potential employer would have to subscribe to the software in order to view its content, and livetext needs to be repurchased after 5 years and Google sites is free.
Sites such as linkedin and plaxo do a good job of keeping all of your email contacts organized, which can be difficult for people with multiple email accounts. Other than this feature I do not see a huge benefit to subscribing to either linkedin or plaxo.
Here is a link to my Google sites portfolio.