I don't know if this is the first WP bookmarking site, whether regular or MU, but here is mine.
I started it a while back on MU, but then fashion blogging was done really well by another, so all I wanted was bookmarking.
I know it will be difficult to get going.
Anyway, the topic is fashion. Nothing in fashion ARTICLES has done very well. (Yeah, good luck to me, heh.) I just really want this to exist.
Anyway, you can enjoy the plugins. Publishing is done on the front-end, btw, for registered users only.
vid1