You could try this block if you wan pupils to uplad file into a my files area. They can share files with other uses, but there is no way to record grades.
Pupil 1 shares file with pupil 2 and 3
They download file and assess it and return it by e-mail or if theyedit the file to add comments eg word reviewing tools or adding text boxes they can then upload the marked file themselves and share with pupil 1
try submission and sharing of files.http://moodle.org/mod/forum/discuss.php?d=33201