You can do an oddball format and actually give one an MBR. It's not standard, but, you can do this. Of course, this does require modification of the code present in the boot sector to support it, but, alas, It can be done. Why you'd want to do this, realistically speaking, I've no clue. Maybe to 'hide' a section of the floppy? I've seen it used on a an ancient copy protected disc once or twice, but, it's pretty damn rare.
Aye. I don't see much point in having partitions on a usb stick myself, but.. to each his own.