There are a lot of ways to keep track of your bookmarks on the web these days. Most of them store your links online as a long searchable list. It great to be able to access them from different computers and to share them with friends and coworkers, or to connect and collaborate with people all over the world. But its still just a big list. Pearl trees has developed something different.
A word of caution:
Like any social media Pearl Trees is a great way to connect with people. If you plan to use it to leave visual bread crumbs for students be careful to monitor your connections as you cannot control which sites other users set as links.