Well my LiveJournal Valentine System has finished now.
The stats are quite impressive - from Monday's start of one user I'd got 3742 at 12:01PM on Friday.
Watching the users and matches grow was very rewarding, and I'm happy the that machine and network handled the load - despite my suboptimal code.
I've now become much more interested in the spread of memes - after watching the site get named-checked in an ever-expanding circle of communities.
I'm working on plotting a graph showing the spread of referrers back to the single start point - it's a little tricky to represent well, but I figure an unbalanced tree would be a good aproximation..