Constant application crashes on 4S running 6.1.2 I have a brand new iPhone 4S, running 6.1.2, consistently crashing applications from core services like iMessage to Evernote and Tweetbot. Phone calls can be sent and received, but experience 1-3 second 'black outs' where I can't hear the conversation. These happen on approx 2-5 minute intervals. I've restarted, hard restarted (hold down buttons for 10 sec) and resynched to iTunes. 

Useful context:
iCloud configured 
Exchange email configured via Zenprise 

I'm glad to do every rational troubleshooting step, I just don't know enough about logging to imagine where to start on this one.
This ended up being a funky one. The result -- something wrong with my iCloud synchronization. It was causing Notes to have hundreds of thousands of copies that resulted in NoMemory crashes. 

Not your textbook issue.. but keep it in mind.