Panasonic just made the first class 10 SD card a few months ago. I'm not saying it's impossible there's a class 10 microsd out there but I've never seen one, but assuming there is, I don't see why it wouldn't work, although I don't know if it would get the true read/write speeds that it's capable of.
good ol' duct tape, my most reliable friend how i think that you are the best invention in the world. maybe some old school hardware hacker could make an reverse adapter for the g1 so it can use full size sdcards. would be kinda ass backwards and defeat the point of it being micro but the internet cred for making it work, priceless