Ahh Yeahh. Apple is having issues with their facetime and imessaging feature. Nothing really specific about whats going on only that sometimes its not working. Is it just your phone or is it both? I'd try doing the 'soft reset' where you hold the power button and the home button at the same time and it restarts. If that doesn't work call Customer Care.
First thing to do is turn both features on in your settings. Don't soft or hard reset it. Many times the phones are not set on for these features.