I love the idea of having a button / icon / text that people could click to "flag for moderation"- glad to see people think about " It could have an option that allows me to set the number of flags needed to send an approved comment to moderation."

Would be even more awesome if such a thing could take into consideration if a user was logged in (And super awesome if it could have options for giving weight to logged in user levels, either editor / subscriber - or s2member type levels, and the new buddypress user levels)

for my usage - on wp site "a" - 3 different non-logged-in-users (from different ip addys) click flag- then unpublish, put in moderation que and send email to admin.

if logged in and role >=contributor then 1 click send to..
if logged role=subscriber - 2 clicks..

This is something we have needed more with our buddypress installs than anything - and a discussion we had a while back put some code out there and got a discussion going around what kind of admin options, front end stuff, etc could / should go into something like this for bp.. the code linked to in the first comment here:
https://buddypress.org/support/topic/report-user-report-abuse-flag-something/
may have most of this kind of code that is needed.

If someone does code up something like this, I hope we can adapt to use with buddypress activity updates / group posts /etc.. I'm sure the bbpress people could use something like this as well (they may have something like it, but I gave up on bbpress couple versions agp, so knowledge is limited)