Why doesn't my wifi on my iPhone work?

I had that happen to my 1st gen iPod Touch. I would select a network, enter a password, and no bars would show up and I had no internet connection. As it’s “condition” became worse, I would select a network, then the network would disappear. That’s when I returned it and got a 2nd gen.

You can do the Renew Lease, which you can see after you click the blue arrow beside the network. Have you tried resetting the network settings? I did that about a billion times, along with restoring the iPod. After that you should just reset all of the settings.

here is my source for doing most of that.

Did you change the router settings from wireless G mixed to wireless H maybe?

Actually, I just fixed my problem. I reset my router and that seemed to do the trick. Thanks for the help, though.