what happens to NSLog info when running on a device? Where does the text go? Does it get saved? Is it therefore a big overhead when running on a device, or does it effectively get sent to null?
Your device will continue logging even when it's not connected to your mac. To see the logs, you need to open Xcode, click the 'Window' menu item, and then 'Organizer'. Then select your device and then select the 'Device Logs' tab. For some reason (for me at least) viewing the logs seems flaky, so if nothing shows up, you may need to completely quit Xcode and restart it.