I'm still not sure what you mean. From whom are you trying to hide your I.P. address? What sort of network are you working on? Most home routers have N.A.T., which effectively masks your I.P. address from external devices. If your router has N.A.T., and you ttry to connect to a website that is outside your home/work network, for example, that external website does not know your internal I.P. address (the address that your home/work network assigns to it); it just knows your router's address on the extranet, i.e., the one that it gets from your I.S.P.
If you don't want for the website (or whatever you're connecting to) to know your real I.P. address, then you can use a proxy, which will prevent anyone who is not particularly determined from figuring out your I.P. address.
On the other hand, computer's don't just go around broadcasting their I.P. addresses. They only reveal them when they try to connect to something. Just knowing your I.P. address won't help anyone much, unless you are running a service/daemon that does something with incoming traffic, and your firewall is allowing inbound traffic on the port that that service/daemon uses. In that case, someone/somebot would use a port scanner to figure out which ports are open on your computer, and if one of them was something common (say port 22 for S.S.H.), the person/bot might try connecting using that method with some common username/password combinations.
If you want to prevent people in your immediate vicinity from detecting your I.P. address, use a network cable instead of a wireless network.
