Sure, how ext3 work for it's journaling is by writing a log of its filesystem transaction to disk every 5 seconds so to be able to recover if the power is cut, there is a crash or whatever...

ext2 doesn't have such feature but then need a full fsck scan in case of a crash which might be painful for a portable device... On the other hand writing every 5 seconds on flash media isn't the best of ideas considering that's over 6M writes a year if the cell is always on (and it will).