Who here (apart from skx) keeps a diary on LiveJournal? I often find myself wishing that the diaries kept here were there. Despite diary rating and the trust metric, I find it in practice much easier to find diaries I'm interested in there than here. I miss the "friends list" facility that allows me to directly choose which diaries to read. And I miss over and over again the facility to make comments on diary entries; where I could make a useful and informative comment, the fact that it will have to appear in my own diary rather than as a comment on another entry puts me off.

Is that feature missing simply because it ain't written yet, or is it a deliberate piece of social engineering? I'm sure there must be some who prefer it that way, but I'd be interested to know why.

I quite often think about what would be needed to really unite all the blogs in the world, so that I can have one "friends page" that follows everything I'm trying to follow. At the moment there's a severe network effect that makes a real LiveJournal account much more useful than accounts with any other provider, even those (eg uJournal) which use the LJ code base. RSS is a component, but it would need a blog-specific module to deliver the same level of usefulness.

Graph Isomorphism

I think there's widespread doubt about the hardness of this problem; ISTR caveats along these lines in descriptions of the associated zero-knowledge proof.