This seems so obvious...
One thing I would die for is an "Auto Wifi" feature/tweak so that I don't have to open up an app, search for a possible open wifi network and hit connect because it'd automatically find the nearest wifi network without password protection and connect to it, in the background. No pop-up window asking you which network you want to connect to, that takes too long.
While you're out and about with the iPod you'll know if there is a non password protected wifi network nearby just by looking at your status bar. No more questions. This would be helpful for people who want to use an iPod or iPad as their primary phone using apps like Skype or Textfree etc. etc.
I'm sure it could be disabled while you're sitting at home or office on your own network, and enabled when you leave so that it's not constantly searching and draining your battery.
Does something like this already exist on Cydia? If not, why not?