I love all my pretty pearls!
I think I like playing with Pearltree more for the visual stimulation, than the utility of the tool. It comes with a Firefox addon that puts some gadgets in your toolbar to help the process.The bookmarks are all public, as far as I know, so you dont’ want to be bookmarking all your private bookmarks. You can add other peoples pearltrees to your own.
My only real issue with Pearltrees is that it uses Adobe Flash, which doesn’t run too well on my Arch Linux x86_64 system. CPU usage is high and now I am down a RAM stick (only 512mb) its just another memory hog. This is just my personal whine though. On any decent setup it should run well.