Unknown IMEI and ICCID issue

Question

I'm going crazy with this. My iPhone 3GS was charging while connected to my iMac. Next thing I know it beeps at me and on the phone it shows the "connect to iTunes" display. I try and connect and disconnect and when I hit the little question mark in the corner is shows that the IMEI and ICCID are unknown. I've never even removed the sim card from my phone.
Then iTunes pops up and says in order to sync I need to put in my iPhone passcode, but when I try that, all the phone will do is go to the make emergency call screen, which it can't even do as there is no signal on the phone. So, basically every thing it is telling me to do I've either tried to do or have not been able to do because it wont let me.

Answer 1

*Try this:*
1.) Take out your SIM card using a paper clip (or SIM removal tool)
2.) HOLD the Sleep/Wake & Home Button until the phone restarts
3.) Re-insert your SIM card (after it's done restarting)
4.) HOLD the Sleep/Wake & Home Button again until the phone restarts
5.) Open up iTunes and connect your phone to your computer
The next thing to try if that doesn't work is the 'Restore' options in iTunes. If restore fails too, then you will need to bring it in to have it looked at.