I do have the 3.3v arduino pro, it is not the mini however. http://www.sparkfun.com/commerce/product_info.php?products_id=9221
Someone had mentioned earlier in this thread that voltage was linked to clock frequency, so thats what I was going off.
I did find a 3.3 volt dc-dc converter circuit that is now in the mail. That should work for sure. I was hoping to keep power consumption as efficient as possible by using extremely low voltage and not needing the loss in a dc-dc conversion, but I'll explore saving power with watchdog/sleep instead.
Thanks.