I think Apple really dropped the ball by not giving us some glanceable way to see missed call/SMS/email alerts without having to push a button, slide to unlock, stand on one foot, twirl a baton, etc. I can appreciate that they didn't want to disrupt the clean lines of the bezel and overall symmetry, but IMO, they had a perfect place for a flashing LED already built right into the phone.
And it goes a little sumthin like this...
If they wanted to get really fancy, they could change the color depending on the alert...blue for email, green for SMS, red for missed calls.
And it goes a little sumthin like this...

If they wanted to get really fancy, they could change the color depending on the alert...blue for email, green for SMS, red for missed calls.