is it possible to open the iphone's settings from within a mobile app?
You can, but only in iOS 5. You can link to specific parts of the settings app by opening special 'prefs:' URLs. See this blog article near the bottom of the page.
Hopefully someone else will chime in here if I'm wrong, but as far as I know that's not possible.
fair enough - no biggy. just thought it would be nice to have a network connection check with a button to open network settings
would be interested to hear and answer for the same reason!