<p>I would like to assign a drive letter to a GMail drive so that I could script some output to it.  Are they any hacks to get this to work?</p>

GMail Drive no longer works (well) -- Google put rate limits into Gmail to prevent this kind of (ab)use of Gmail.  It's like being attached to a hard drive over a bad satellite connection to Rwanda*.
You might look into Amazon's S3, which is a cheap web-hosted data storage service; then ask this question again from an S3 perspective.
* Incidentally, that's what I deal with at work on a weekly basis.