EXT3 is a linux partition.
http://en.wikipedia.org/wiki/Ext3. For those who use linux you can make another partition on your memory card in ext3 format. The guide basically explains how to mount the particular partition and provides the required libraries and files.
I have'nt got down to doing it yet, presently dont have linux on my laptop and cant seem to telenet to my E6, you need to get this done in telnet. As soon as I do it will post a detailed guide.
But from what I gather, if you format your card in linux into 2 partitions one of FAT16 and the other of ext3 and run the script it'll automatically mount for you.