So.... use an unsupported FLASH memory device like I did.  I had a few that were useless for ReadyBoost but this got them working. 

Plus, I'd like to know if I can use more than the 4gb restriction by changing some of the other registry entries at this path.  Even though MS developers say that performance is only noticeable on Vista machines w/ around 1gb memory... still cool to know. 
Regardless, it may save my laptop battery a bit.

So don't hate, participate.

Also, still trying to figure out if it's a performance gain if I'm not using a ReadyBoost device that meets their IO bandwidth requirements: