Split it into a small FAT partition and a bigger UDF partition. If you can't write to UDF, save files back to the FAT partition instead. This variant works on computers where you have no admin privileges.
I'm still not sure how this is easier than ntfs-3g.
On Windows > XP, not at all. On XP, a little tougher. On OS X and Linux, much better, because you don't need to install a new piece of software to access, and native UDF is much faster than ntfs-3g.
Wait until a read/write driver for exFAT [wikipedia.org] hits OS X and Linux (Linux already has a read-only driver for exFAT)
In what way would this be better than a read/write driver for NTFS?
It will probably be much easier to develop an exFAT driver in kernel space, because it's very similar to FAT. This will, again, give a performance benefit relative to ntfs-3g
No amount of careful planning will ever replace dumb luck.