Is there an iOS4 app that when clicked will perform the same function as Settings->Airplaine Mode on/off? I have issues with my iPod Touch 4G where it disconnects from the access point for no apparent reason, and I need to go into the settings app and toggle the airplane mode to get the wifi working again.  

Is there an app that I could run to automatically turn the wifi off and then turn it on again so that I don't have to waste so much time opening the settings and toggling airplane mode?  I haven't been able to find one in the appstore.
Not without a jailbreak.  If you get a jailbreak there are various ways to do things such as switch airplane mode on/off, adjust screen brightness, turn wifi/3G on or off.  The app SBSettings is one such example.  You'd be better off diagnosing your AP problem than jailbreaking your phone for just this feature though in my opinion.