Alright, let's get this out in the open. MagikRevolver, you need to start listening. One device per SATA port. Just one. Unless you're using a RAID controller at the other end, in which case there is still only one 'drive' visible to the single SATA port.
One drive. One cable. Sorry, no matter how much 'research' you've put in, or how you 'know it's been done before'? You're wrong. Unless you use one of the external chassis' with their own RAID controller, you will never be able to connect more than one HDD to one SATA port.
Princess is correct. MagicRevolver.... listen to these guys. I am an engineer and i can confirm that everything they say about 1 sata drive per port and a controller showing one drive when, say, are corrected to the hub is correct. (not that you need an engineer to confirm that).
You are best to get the converter that hiphop discussed and then have an external SATA drive.
On a side note.... I have a gigabyte I RAM. Removed it from my computer and put in temporarily in the PS3. Very fast... but too expensive an exercise and only 4 gig max storage> Was fun to try though.