On Social Bookmarking

I’ve begun to think that I want two different sorts of bookmarking service:

1. For reference links – pages I refer to frequently and that I want to be able to find quickly when I need them, from any computer. Ideally, these should be listed within a drop down menu in my browser. I use Google Bookmarks for this, and it’s great as it integrates neatly into my Firefox menu bar. If I’m somewhere unfamiliar, I browse them via the iGoogle widget*.
2. For interest links – pages I found interesting that I’ve now read and probably won’t need to read again, but that I might want to revisit sometime, or maybe pass on to other people. This solves the ‘oh, I saw this really cool page once but now I can’t find it’ problem without relying on 100 different favourites lists on 100 different web apps. For these, I want to be able to quickly tag things and throw them in a pile. If I need to find something later, I’m generally fine putting in a little effort to discover things. It’d also be nice to have some sort of chronological order so I can go back in a time machine and see what was amusing me in life in the past. Finally, I want to be able to pass things on to my friends, and have lists of ‘interesting stuff’ that I can feed into my blog.

I’m currently looking for recommendations on a service that fits the second problem – does anyone reading this have particular opinions? I’ve briefly used both del.icio.us and Magnolia in the past, but failed to fit them into my browsing habits, mostly because I was trying to use them to solve the first problem rather than the second.

* I’m a bit of a Google whore – if I’m using a computer on the net for more than 20 minutes, I’ve invariably logged into one of the various Google services..