Social Bookmarking                                          -*-org-*-

Is there any social bookmarking service that provides some of the
functionality I hope to implement in blink?

* Requirements

- Easily extract my links
- Filter links by category
- Filter links by access time
- Back-level browser support
- Non-commercial
- Open source
- Accessible from work

* Alternatives

** delicious.com

** Wiki

PBWorks? YukiWiki?
** Pinboard

pinboard.in is an excellent service that does most of what I
want. Only registered yesterday, but the only shortcomings I see are:

- Style has too much white space, requires scrolling when window
  small.

- No URI access "marking". Can only sort bookmarks alphabetically or
  by creation date.