Using Multiple IP address in a single PC

I have several new Laptop PCs. I would like to be able to use these PC at any of our stores and the home office. We are using NT as the network. The home office is DHCP or TCPIP. The stores are TCPIP only. Each store has a router. I want to beable to roam from store to store without have to change the IP settings on the Laptop.

Is this possible? How is it done?