There appears to be a problem with the WiFi connection on the Apple iPhone and iPhone 3G. iPhone Atlas first reported this problem and has apparently received an overwhelming response from their readers commenting on this issue.
One reader commented…they have a first generation iPhone 8GB and a WiFi network in their house that gives connection to their laptop from across the road, but with the iPhone it has to virtually be held over the Linksys to get a WiFi connection.
Another says…My iPhone 3G loses WiFi connection intermittently, sometimes coming back on its own other times not. Often other wireless networks appear and sometimes not.
So there does seem to be a substantial problem with the Apple iPhone WiFi, and the word is Apple is replacing iPhones with WiFi problems noting “Hardware issues.” More of these comments can be found at source.
Source — iphoneatlas