Mark,

>I have a battery power PIC application that I have the opportunity to reduce
>the power by running the PIC at 3V. I looked at Linear Technology, Maxim,

A linear LDO regulator is probably your best bet, the only reason I would
go with a switcher is if you needed supply voltages higher than Vbat. We
use MAX666 and MAX667 in SO-8 packages. If your system can be powered off,
you can also use shutdown to really conserve power. Also, are you utilizing
SLEEP on the PIC? Are you making sure that the ports are not sinking current?

-dn