propigate your own database with the information using some kind of webspider or something..

I have considered this idea and even included the bare thoughts for it in LochJournal back when it was still LJU, but I canned the idea when I realized how hard of a hit it is on the DBs to do that, and how fast Brad would sitelock me. ;) But, if you're going to do this, why not just use userinfo.bml to convert their userid to names and stuff? I think userinfo.bml has a method to convert userids to usernames. I think. Hmm. Either way, good luck. You will probably want to ask Brad first. :P

We've done a lot of graphical / path-finding analyses, and we've found that they're basically unfeasable.

Graphing: Even graphing the relationships between just the list of all of the people on my friends list was a 2000x2000 pixel image littered with lines, and it brought my 800mhz Athlon to its knees. (I was using graphviz, which is pretty state-of-the-art in terms of graphing software.)

Shortest path: Unless you can propose a previously-unheard of algorithm, anything you do will be a horrible hit on the servers.
There are almost 400,000 users, and the hardcore users have over 100 friends each; that's a possible 40,000,000 links.

Most importantly (and also a response to your earlier lj_dev post): some people hide their friends list, for privacy purposes. (Like me.)


Finally, if you spider the database, I think dormando will murder you in your sleep.
We used to export friends list data for interested parties like you, but some people started abusing it.

Mail me privately and I'll give you some data to play with.