Is there a way to keep my iPhone from receiving calls/texts/alerts while listening to music? I like to listen to music on my iPhone when running, but it's really annoying for the music to be interrupted by calls/texts/alerts. I know I can put it in airplane mode, but that will keep me from using the GPS to track my mileage through apps like RunKeeper. Is there another way to "silence" calls/texts/alerts and just have them show up as missed when I'm finished listening to music?
Coming in iOS 6, you'll have the option to set "Do Not Disturb" mode in the device's Settings.  DND allows you to block out a time window where calls and alerts will be silenced.

You can optionally configure it to allow calls from "favorites" or repeated calls to still come through.