Does this app support connections to multiple different gmail accounts at once, or just one at a time. I tried to tinker with it for a moment but could only get it to have one drive at a time actually active, and each account is treated as a separate logical drive. Is that the intent of this app (and a limitation google has placed on simultaneous connections from 1 person) or can(or could) it handle multiple accounts at once. If it could, you could make this app -soo- much more by merging all the accounts into one logical drive (aside from just a virtual drive of any size). From here break large files into chunks and upload them to different accounts(want to upload faster? Just add more accounts and open more connections. Same goes for faster downloads. Effectively upload and download data as fast as your connection can handle from anywhere to anywhere) You show these chunks on the gmailFS as just the one logical file they all came from, but as you're breaking it into chunks and naming said chunks that shouldn't be hard at all. You're already abstracting gmail attachments to files, what's one more layer of abstraction.
Want to share data with a group of friends? make a list of account names/pw's to share and you can all upload to and download from a shared drive. Ideally make it so you can share lists easily(maybe even email them & allow them to be added with a confirmation window next time you sync with the account)
Adding more accounts and distributing chunks to those accounts or backing up data you've uploaded is easier than with most types of online storage solutions: simply forward what you've got uploaded someplace elsewhere, either some chunks to a new account to allow opening more connections to grab the same file or even forwarding everything to some backup set of email addy's.
If gmail somehow limits how many connections you're allowed to have open at once, could some sort of proxy service help(slap in a list of free anonymous proxies and each connection to gmail appears to be coming from a diff IP, would add a pile of latency, but enough connections and you should still get good data throughput.)