they didn't publicize it all, but iPhoto 2 has the ability to store libraries elsewhere. if it doesn't find one in "Pictures" it asks you to "choose a library."
this worked fine on an external firewire drive on my powerbook. however, storing outside of Home on the internal drive of my iMac does not work.
(Sees the library--the pictures in it, can't add to it, though, or edit anything.)
-matt