+"Emergency Calls+
+If iPhone is locked with a passcode, you may still be able to make an emergency call.+
+Make an emergency call when iPhone is locked: Tap Emergency Call, then dial the+
+number using the keypad.+
+Important: You should not rely on wireless devices for essential communications, such+
+as medical emergencies. Use of any cellular phone to call emergency services may not+
+work in all locations. Emergency numbers and services vary by region, and sometimes+
+an emergency call cannot be placed due to network availability or environmental+
+interference. Some cellular networks may not accept an emergency call from iPhone if+
+it doesn’t have a SIM, if you locked your SIM, or if you haven’t activated your iPhone."+
From Page 39 of the iPhone User Guide
http://manuals.info.apple.com/en/iPhoneUserGuide.pdf