A delicious replacement that uses twitter syntax to organize stuff - i.e.: hashtags and @people. App integrates with twitter for both tweeting bookmarks that you add, and importing links you've tweeted previously as bookmarks.

Not at all complete (both features and fixes to be done), but solid enough that I use it every day for myself to organize links that I use for references, collect things that I'm researching, to create a "to-read" list, and so on.

It was learning foray into bootstrap and jquery, and has gone pretty well.

Right now, its sign in through Twitter only. I'll add native account creation at some point, but you're more than welcome to try it out in the meantime.

Edit: Screengrab of Linkthing in action http://imgur.com/Rrr0g