[p4] A tool to list all files that haven't been added

[Taylor Brown]

Is there a GUI tool out there (or a way to do this in the Perforce GUIs)
that allows me to see, at a glance, the difference between my perforce
depot and my local drive?  In particular, I need an easy way to see
which files I have forgotten to add to Perforce.  When you all need to
guarantee that your checkin won't miss any new files, do you just
recursively add files that match particular wildcards? For example:
Recursiveadd.bat *.cpp
Recursiveadd.bat *.h
...

This could work, but I'm still worried it could miss the oddly named new
file. 

I'd love to have a tool to recommend to our devs as a best practice
before they do their checkin.  I am guilty of performing a checkin,
syncing to a clean branch, testing, and then adding the files I forgot.
Although I work in my own branch, I still don't like the idea that I'm
breaking the branch until I get all my files checked in.  I'd rather it
be more atomic.

What I _really_ want (and now I'm dreaming) is a Beyond Compare plugin
where one side is my local file system and the other is my Perforce
depot...Now THAT would be a tool.

Many thanks for any advice or assistance,

   Taylor