I was wondering what the cost would be to fix the wifi hardware on an iphone. I am sure it is not a software issue.
First, I'd make sure that you've got iTunes and your firmware up to date. If that still doesn't work, there may be a hardware issue. For an iPhone 3G, we could likely do it for under $60. To be sure, we'd need to have your device in front of us for an evaluation. That can be purchased here: http://www.milliamp.com/iphone-repair-evaluation.html
Once it picks up a wifi signal it will ask u If u want to connect. u dont have to have and cellphone plan at all for wifi to work (If that ur acual question)