Switching branch before commit

I know this is probably a FAQ and I thought I found it somewhere once,
but... How do I commit changes from in my working directory to another
(possibly non-existent) branch?
 
All too often I am working on changes and realize I am sitting on master
or a topic branch and I need to commit my mods to different branch.  I
really don't like:
 
    git commit
    git branch <other-branch>
    git reset --hard HEAD^
 
Is there anything like:
    git commit -b <other-branch> [<file>...]?

If not, would patches to implement such a change be accepted?