The original thread is from Russian forum motofan posted by whitemoto. Now we can easily split our SD card in FAT/EXT3 partitions. The next version of the Russian monsterpack The One will have full support for that (and I bet all future modded firmwares too).

Note: That is a guide for Linux users only. Windows machines cannot deal with EXT3

Steps:
1. First start with mounting the memory card: mount /dev/sda1 /mnt/sda
2. Make a complete backu (it will be formatted remember) and unmount it: umount /mnt/sda1
3. Start fdisk (that is utility for managing disk partitions): fdisk /dev/sda
4. Type "p" to see the current list of partitions
5. Press "d" followed by the number of the partition in order to delete it. Verify with p again
6. Now for the example we will create a FAT partition
- Type "n" to start creating new partition. It will ask you for extended or primary partition - type p;
- Type the number of the partition (eg 1 as it is first partition)
- It will ask you for Cylinder - type "1" as we start from the beginning of the flash card
- On the question for last cylinder type the size of the FAT partition that you require (+200M for example)
- Test if it is created successfully with p
7. Now we will make a SWAP partition
- Type "n" for new partition
- Type "p" for primary partition
- Type "2" as it is second partition on the SD card
- On the first cylinder it will load the end of the FAT partition by default
- Again type the size of the partition (+50M or whatever you want)
- Type "t" to change the partition
- Type "2" to select the second partition that we just created
- Type "82" which is Linux SWAP
- Type "p" to verify
8. Create the EXT3 partition:
- "n", followed by "p" and "3" again
- Enter on the default first cylinder (loaded the end of the SWAP automatically)
- Enter on the default end cylinder (loaded the end of the free space automatically)
- Type "p" to verify. Usually it will load partition type 83 (Linux EXT3) by default. If not - type "t -> 3 -> 83" like in the previous step for the SWAP partition
9. If everything is ok - type "w" and it will do it. If you made a mistake - you can always quit prematurely with CTRL+C or with "q" and start over.
10. Now in /dev we have sda1, sda2 and sda3. We need to format them
- "mkfs.vfat /dev/sda1" command will format the FAT partition
- "mkswap /dev/sda2" will format the SWAP partition
- "mkfs.ext3 -j /dev/sda3" will formwat the EXT3 partition
11. That's it. You can respectfully mount those partitions on your phone by telnet connection. The new "The One" monster pack (comming soon) will fully support that configuration on boot.
You can follow the Enable support for Linux partitions tutorial to make it yourself too

P.S. Here is additional information for those who do not know how to enable the swap:
// Creating swap file on the second (the swap partition)
# mknod -m 660 /ezxlocal/home/mmca2 b 243 2
// Enable the swap file
# swapon /ezxlocal/home/mmca2

You can put those two commands on your autorun file. Additionally using "swapon -s" you can check your swap file usage details