Who: Students could correspond through these first-person video diaries within a single classroom or school, or across greater distances. Correspondence between students and school faculty might also be fruitful.
What: Participants' video correspondence could potentially be organized around a theme (like civic engagement), or around the project of identifying the common threads in their otherwise seemingly disparate experiences. Students could document snapshots of their everyday lives using a "show don't tell" approach. Perhaps their video correspondence could serve as a precursor/scaffold to a greater collaborative effort of some kind.
When: I imagine the time commitment would be fairly flexible. Videos would be only a few minutes and students could create them once a week or once a month depending on interest, resources, implementation context, etc.
Where: I think this could work as a school activity, but it may be more effective and easier to implement in a more informal learning environment .
Why: While correspondence may be limited to partnerships (though not necessarily), I think this style of communication has the potential to increase students' (and perhaps also teachers') capacity for empathy--and consequently their ability to effectively collaborate--in a more generalizable way. It could help them see beneath the surface of their assumptions about others, and to recognize commonalities among differences. I think it could also enhance collaboration by helping to empower introverted or shy kids who might otherwise be reluctant to share their stories and give a voice to their ideas in more conventional face-to-face formats.