As the Counselor, I do not have a regular classroom, but work with all students in the school. One collaborative project that I could do with the upper elementary grades would be to work on the issue of Bullying. This project could raise a student's understanding of Bullying and the everyday things that they might be engaging in that could fit and/or actually be examples of bullying.
The students could make Word Wordles, Animotos, use Google Docs and Drop Box to share ideas, definitions, examples and ways to stop bullying. The classes within a grade level could share or could share with a different grade level.
In the primary grades, this could also be done either with the subject of bullying or any of the Life Skills.