three hds? is this possible?

[TheCreator]

Hello list,
I read somewhere on google that it was possible to hook 3 hds up to a system with out the raid card.
It said that you could disconnect the cd drive, and use the IDE cable from that to hook up a hd.
My problem, is I'm running out of room. I've got like 38gb of music, and other files, and my hd is only 40 gb.
My idea was to move some folders that are expanding like the music folder to the other hd, and then mount it in media where the normal music folder was, and call it music.
Any help would be appriciated.
I tried hooking it up to the ide cable on the cd drive like it told me, and it didn't register it.
Thanks,
~~TheCreator~~