You'll find it here: http://www.livejournal.com/friends/nudge.bml
Although that only lists the people who haven't updated in the past week. Or for a week or more, rather.
Huh, rather, make that, you can't nudge people who have updated at least a week ago.
The interesting side effect of this is that with this ability, you can check to see if people have been posting friends only, and not letting you see their posts. Granted, there is no way around this, unless they disable the week limit checking..
