I actually searched for a very long time for something like this. I finally decided on a speaker dock (JBL Onstage III for iphone) there is no feedback and no need for airplane mode. It's a great little dock (battery and AC charger) perfect for traveling. The added bonus is it charges your phone very quickly and comes with a remote.
I also bought a $0.99 app called Alarm Tunes. it stays lit while charging (doesn't sleep) you can also pick which music from your iphone library that you would like to wake up to.
I find this combo the best because it's compact enough to take with you traveling.
Hope this helps.