[Ti] Advice please

[Suzanna]

  I have an iMac and a Powerbook with a broken disc drive. I use my  
powerbook as a back up and when I travel (not often).

My question is, when I upgrade to Leopard on the iMac, will I still  
be able to use the powerbook for back up etc with only Tiger  
installed on it?

OR is there a way to install Leopard on it too, using a method other  
than a disc install? Maybe thru firewire somehow????

Thanks in advance for help!