Question: So first here's the problem. I used to be a Blackberry user and could selectively turn things silent/off/loud but with the iPhone it seems to be an all or nothing deal. I run a small company so I need to be able to be reached in the event something goes wrong and I'm sleeping. My old system for this was to turn everything to silent except for voice calls which would play a loud ringtone to wake me up. I don't get many voice calls except for work related stuff so this worked perfectly.

The question is can I replicate this somehow on the iPhone? Even if there was some kind of app that could play a noise and notify me when someone needed something. I know it's possible based on [this StackOverflow question](https://stackoverflow.com/questions/2913185/how-to-play-sounds-in-locked-mode-on-iphone) but short of writing my own app is there anything out there that can help?

Answer: 
You can use [Find my iPhone](http://www.apple.com/iphone/built-in-apps/find-my-iphone.html) to remotely play a sound, even if your phone is in silent mode. Requires someone to trigger it in the web interface or iOS app.
I haven't tried this but ... assuming you are running iOS 5, under Settings -> Sounds where you can pick a tone for each kind of alert, it looks like "None" is a choice in all the categories. So you could turn off sounds for everything except the Ringtone.