Years ago I bought an Amiga 500+ with loads of games, one of which was Sim City. I thought it was tough going with my buildings being destroyed all the time by natural disasters. It soon improved when I found the code booklet, which was printed in dark red with maroon letters to stop it being photocopied. Other games like Microprose F1 GP would ask for a word to be typed from a random part of the manual.
Monkey Island 2 and F/A-18 Interceptor had a code wheel, and annoyingly trying to play Another World on my GP2X handheld emulator soon had it asking for codes. It's not so handy having to print 20 pages of gibberish symbols out.
I've tried it in the past on Vodafone in the UK. If subscribed to message service # 50 (cell info) it would display the local landline area code (e.g: 0161) on the screen in standby. Fairly useless and the phone manual said it would use more battery life.
Perhaps the network operators could send out an SMS that auto configures your phone to subscribe to emergency alerts, like they do for enabling WAP browsing etc.