IP Settings Home vs Office

I have a laptop computer that I use both at home and at the office.  At the office I use DHCP/Obtain IP address automatically to get all my correct addressing.  But at home I have DSL service from Pac Bell with static IP addresses.  So I have to program in the IP addresses at home and then reboot.  Does anyone have a seamless means of automating this switching back and forth?  That is at home I boot up and I have my static IP addresses ready to go but at work I use DHCP.  I was thinking perhaps I could double click a .reg file at the end of the day that would change the IP settings right prior to shutting down.  What would that .reg file look like?  Or perhaps you have another method that might be even easier - like a DOS menu popping up on bootup where you select home or office?
Looking forward to your reply.