If you want to see all commits on all branches that aren't pushed yet, you might be looking for something like this:
git log --branches --not --remotes
And if you only want to see the most recent commit on each branch, and the branch names, this:
git log --branches --not --remotes --simplify-by-decoration --decorate --oneline
From here http://stackoverflow.com/questions/2016901/viewing-unpushed-git-commits#answer-3338774