I have just had a prowl in iPhoto help and in fact it explains how to set up multiple libraries and select the one you want when you open iPhoto. You can not switch libraries on the fly, sadly.
Severin Crisp
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                    Assoc Professor R Severin Crisp, FIP, CPhys, FAIP
       15 Thomas St, Mount Clarence, Albany, 6330, Western Australia.
                      Phone  (08) 9842 1950   (Int'l +61 8 9842 1950)
                             email  mailto:[EMAIL PROTECTED]
                        Web pages http://www.JennyCrisp.com.au
                          &  http://members.westnet.com.au/Crisp
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