The reason I called it low cost is because you still have to pay for the hardware.   Here are the steps creating an iscsitarget.   It works with Windows XP.    I will have to test it with ESX, Linux, Windows 2003 and Windows 2008.   Here are the steps:

1) Install Ubuntu 9.04 onto your workstation
2) Partition your drive according:

      first primary partition         -  /boot filesystem 200MB
      second primary partition  - 1GB Swap
      third primary parition        -  /        filesystem 20GB
  
      Of course the partitioning of your drive is completely at your discretion.

3) Open a terminal session and login as root (su -).
4) Type fdisk -l
5) Type fdisk /dev/<your disk>
     Use the following options:
            n <enter> - create new partion
            p <enter> - set partition type to primary
            4 <enter> - set partition number to 4
            Hit <enter> twice to accept the default for the beginning and ending of the drive or cylinder.   Whichever you choose.
            w <enter> - write the partition table.
6)  Type partprobe - this will reinitialize the partition table without rebooting
7)  Type pvcreate /dev/sda4 - Creates the LVM Partition Volume on the physical drive
8)  Type vgcreate vg1 /dev/sda4 - Creates the LVM Volume Group
9)  Type lvcreate  -L 100GB -n data1 vg1 - Creates a Logical Volume on the drive
10)  Go To System > Synaptic Package Manager
11)  Type in the sudo user
12)  Search for iscsitarget and install
13)  Type in sudo gedit /etc/default/iscsitarget.   Enable the iscsi target by changing the first line to ISCSITARGET_ENABLE=true
14)  Of course you can change the other options if your environment calls for it.  Type in sudo gedit /etc/ietd.conf.                                                  Change the following lines:
                 Lun 0 Path=/dev/vg1/sandata,Type=fileio - You can have multiple luns and change the path
                 MaxConnections        3 -  You can change the number to any number
15) Restart the iSCSI Target - /etc/init.d/iscsitarget restart

You should now able able to cluster using any using Linux, Windows 2003/2008, Netware and VMware ESX.

Enjoy!!!!!

Companies such as Starwind and Datacore still have there place.   They make really good products but they are costly.