I'd like to put an end to this.
Attached is e2fsprogs (tune2fs, e2fsck, resize2fs, and mke2fs) built for Android/ARM. You should also use the "-t auto" mount option so that it's still backwards compatible with ext2.
To convert your ext2 to ext3, you can simply run "tune2fs -j /dev/block/mmcblk0p2" after you have these tools on your device, and reboot (assuming your ramdisk allows for mounting as "auto"). You should unmount and e2fsck the partition first, if it's not been checked for errors.
Step by step by neoobs