Scoop.it! has been around for a while, but just recently i started my own Scoop.it! and i must say, it has been a good way to collect the best tweets on one topic and share them.Teacher could also collect good links example geography or history class for students or you can create Scoop.it! for whole class.
You can also follow easily other Scoop.its.
Education Technology - theory & practice
iPads in High School
and one for my Finnish colleagues:
Tutorial by Russel Stannard:
To get started, check this great video tutorial:
Scoop.it! tutorial: teachertrainingvideos by Russel Stannard
That is all you need!