Hiding or faking my IP address?

Hey, can someone help me with this? I need to hide, or at least fake, my IP address. Is there a program that does it?

Also, does simply restarting my computer change my IP. Power-cycling my cable modem would definitely do it, right?

The reason is there is a mean-spirited mod in another forum who keeps banning my new accounts I register. I mean NO ill-will to the site at all. He's mean to a lot of people. Typical power-hungry kid in college thinks he's all that.

Also, I don't understand how he can tell it's me because I recently moved and now have a totally different ISP. I think he's just guessing.

Please help! Thanks to all...