Site-blocking subscription services?

I checked through the FAQ and didn't see it, but thought I'd ask to
make sure -- is there any functionality in Squid to support
connections to web-surfing access control services? Anyone working on
it? Thanks!

        -Mike Pelletier.

--
 "[It will] be very hard to increase browser share on the merits of
  [Internet Explorer] alone.  It will be more important to leverage
  the OS asset to make people use IE instead of Navigator."
			-- Christian Wildfeuer, a Microsoft Manager