arch from Terminal return
i386 which would seem to indicate I'm not in "64-bit mode" when I know based on my processor I'm running a 64-bit Mac? What does that actually mean and how am I supposed to use the
Did you hold down the 6+4 keys when booting? Even when running a 64 bit capable Mac (which I am as well) Snow Leopard (I presume) defaults to a 32-bit kernel unless specifically instructed to load a 64-bit kernel, in order to maximize device driver compatibility for legacy devices. Mac Pros, I believe, will boot into 64-bit mode by default, as will the XServe.
See this link for details.
Edited to add: