Add memory to Toshiba HD-A30

I’m sure this is a stupid question, but it’s bugging the crap out of me and I can’t find an answer. I have a Toshiba HD-A30 and I was wondering if there is anyway to add more storage memory to it? I know its a dead technology, but I would like to download any downloadable content for the HD DVDs I own. Especially since it seems like Universal took down their content. I want to get what I can while I can, but some of the movies (Transformers, Knocked Up) have so much they fill the pitiful amount of space this shipped with. I already tried using a thumb drive in the usb port, which I had the felling wouldn’t work but I figured it was worth the shot. Is there any chance of adding more memory? Or was that a feature that just never got implemented?

Also what the heck is the usb port for if not for adding memory?

Any help would be greatly appreciated.