I am traveling right now and while I travel I need WiFi, who doesn’t? I don’t want to pay, why do you need to pay. Well some networks are unsecure, like private airport networks. They usually proxy port 80 and 443 for web traffic and change your via Captive Portal.
All you need is access to an ssh server. Some hosts like justhosts.com offer shell access. Just ssh to your ssh server and forward traffic on a dynamic port, say 555. Have your browser listen on port 555 and you have free WiFi.
This is a simple tick, other networks like Boingo allow the iPhone to have free access. For this you need to change some browser settings. Click here for more details.