What will you need?
A. Any standard SATA SSD 
B. Any standard SATA, USB, or FireWire HDD
C. Mac or (Hackintosh with Clover v2 UEFI Bootloader)
D. Mountain Lion 10.8.2 Installer USB (or another Mountain Lion 10.8.2 bootable drive).

Lets, get started...

1. Boot from the 10.8.2 Installer USB, format both of the drives you want to use with Disk Utility.

2. Open Terminal and type "diskutil list". You need to make note of the BSD drive locations for the two drives that will be used. Ex. disk0, and disk1

$ diskutil list
3. In Terminal Type "diskutil cs create "Fusion Drive" disk0 disk1" this will fuse the drives together.
$ diskutil cs create "Fusion Drive" disk0 disk1
*** Wait a minute. You should see scrolling output about whats happing to your drives in Terminal.

4. Once the fusion of the two drives has finished, in Terminal type "diskutil cs list" this will show the layout structure of your new CoreStorage (LVG) Logical Volume Groups.

$ diskutil cs list
5. You won't be able to create the first partition on the new (LVG) Logical Volume Group with Disk Utility. In preparation for the Mountain Lion 10.8.2 installation, in Terminal type something like this "diskutil coreStorage createVolume D1E3474F-4E7-4F26-9Z77-1A2BADF3CD45 jhfs+ "Macintosh HD" R"
$ diskutil coreStorage createVolume <UUID> jhfs+ "Macintosh HD" R
*** You will have you use your own (LVG) Logical Volume Group's UUID to complete step 8 correctly.

I don't want a Fusion Drive anymore, how to defuse?

1a. If your Fusion Drive is the startup volume, then you will need to boot with the Mountain Lion 10.8.2 Installer USB or another OS X 10.8.2 bootable drive. Once in Terminal type "diskutil coreStorage revert <UUID>"

$ diskutil coreStorage revert <UUID>
*** You will have you use your own (LVG) Logical Volume Group's UUID to complete step 1a above.