hate to tell you, but this change is dead simple on a Mac
I leave my wireless network open though. When I moved in I had to wait a week for my DSL to be installed. I used my neighbor's network during that period. When I got mine up and running I left it open. I'm not running any servers on my wireless network and Macs are pretty secure. I think of it as a public service. I don't get charged by the bit, so what's the harm? If someone does something untoward, safe harbor should cover me.