If you are uncomfortable with your friends knowing you're carrying, I think you should re-think whether you should be carrying. Everyone I interact with regularly knows I carry, and I don't hide the fact from friends. I have yet to lose a friend over it (and doubt it would ever happen). Worst case I've had was someone who was absolutely stunned by the fact that I carried, but she certainly didn't care and it didn't affect our friendship. Though, she just got her CCW recently (through me helping her along and talking to her about it) and will be carrying as soon as she can afford her new gun.
For me this is a non-issue. I'd be more embarassed by the fact that I got pulled over in front of my friends, than the fact I'm carrying. Besides, I live in state that doesn't require notification.