I have one, but it's not public -- at least, not yet. One of the hardest things to get right here is search. It's easy to drop in a full-text search solution, quite another thing to design search that works well.

My system is a tiny app that automatically grabs pretty much everything I do on the Internet and indexes it. Github stars, HN posts, Facebook likes, bookmarks, you name it.

I can optionally tag or add my own sticky-notes to anything, and there's some other neat tricks that make fuzzy searching a lot easier. Human memories are very story-based, and so if I only remember that I looked at something important about ducks when I was at a Meetup, I can actually search for that.

I'm considering productizing this -- email's in the profile if you'd like to chat. :)