Diigo, et al

www.diigo.com/
good site for sharing new technologies...

also...
www.ilearntechnology.com/

and...
www.howtoons.com/

and...

www.kineticcity.com/

maths...
www.ixl.com.com/

all curriculums....
www.curriculum21.com/

rubrics....
http://rubistar.4teachers.org/