Use a custom HTML start page for the Playbook Web Browser! (Think Chrome SpeedDial)
Bookmark management? Sucks. Chrome SpeedDial? Rocks. Can we get this experience on the playbook? Yes (kinda).
Basically, create a page in html with widgets, links to all your favourite web destinations, and whatever else you fancy. Put it on your playbook, type "file:///" into the Playbook Web Browser, find your start page (/accounts/1000/shared/whereveryouputit), open it, and set it as the home page. Voila.
Currently, I'm using a modified version of this lovely piece of work by Gocom...
Estacado start page by *Gocom on deviantART
... but this little piece by flatmo1 also looks amazing as the start page of the Playbook Web Browser.
EIGHT - start page - UPDATE by ~flatmo1 on deviantART
Good luck have fun.