New Visual Tool for Indexing Web Sites

I stumbled upon this app (www.PearlTrees.com) and have found it to be a very functional and cool method for organizing and sharing web sites.  It has an iPhone and iPad app that I use to add sites to my tree, seen above and accessible here - www.PearlTrees.com/rhettdean. I have added and will continue to add sites I find valuable. It is a useful tool for anyone (teacher, speaker, corporate trainer, etc.) who is in the business of aggregating and sharing information on the web. I have used http://Delicious.com/pliblog for years to index content I find valuable.  However, Delicious doesn't do a good job of visually representing the information or of just showing the source web sites.  PearlTrees does.