As of the last few months, my phone refuses to find most public hotspots, but will generally connect to home wireless networks. For instance, I can connect to my home wireless and my girlfriend's home wireless, but if I go to a local place like Starbucks that I know for a fact has public wifi, my phone won't pick it up. Restarting the phone doesn't fix it.
I haven't updated to iOS 6 yet. Could that potentially fix the problem? IS there a different problem that could be causing my issue?
I'd go into settings and erase all the stored SSID/passwords by choosing:
General > Reste > Reset Network Settings
At that point, you would need to try joining the network and be prepared to gather more information about that location. Do other iPhone work with the router, can the router be rebooted (or checked to be sure that there are DHCP leases available - many routers issue only a fixed number of valid IP addresses).
You can troubleshoot things quite well following Apple's guidance too:
