How can I view any local commits I've made, that haven't yet been pushed to the remote repository? Occasionally, git status will print out that my branch is X commits ahead of origin/master, but not always.

Is this a bug with my install of Git, or am I missing something?

This gives a log of all commits between origin/master and HEAD:

git log origin/master..HEAD

When HEAD is on the master branch, this gives a log of unpushed commits.

Similarly, to view the diff:

git diff origin/master..HEAD