Just started using del.icio.us

[LeperousDust]

It's all working fantastically integrated with opera, but before i really start using it properly and tagging all the weird and wonderful sties i want to remember but not to clutter my core bookmarks, is there anything better out there?
For instance delicious only has flat tags, for instance Linux and Ubuntu are totally different, I think Ubuntu should be nested under Linux etc...
Anything like this out there, i'm having a browse around Blinklist now but i dont see much difference...