Network Setup Question

[Doug Hardie]

I have a bit of an unusual network setup situation.  I have a machine  
that is only used to store backups.  It gets moved around to  
different locations occasionally so it has to be able to live on a  
192.168.1.x or a 10.0.1.x network without reconfiguration.  I also  
need a fixed last address byte so I can connect to it remotely.  I  
initially set it up with DHCP and then used an alias for the .250  
address on both networks.  That worked, but caused problems for the  
local network in one location.  The particular user couldn't  
understand why sometimes his computer got different IP addresses.  So  
I tried to establish the 192.168.1.250 as the primary address and  
added an alias of 10.0.1.250.  That works  in both environments  
except that there is no default route.  Is there a way to negotiate  
just a default route via DHCP and not an IP address? or is there a  
way to set the default route based on which IP address is in use?   
Thanks.