i know this doesn't address unlocking the fm tuner, but as an even better alternative i think, i use the site
http://tuned.mobi/ which lets you listen to the internet streaming version of most fm stations, site is formated nice for mobile browsers and you tune in your favorite radio station anywhere
now what i would love to see on a cell phone is an fm receiver & transmitter! so i can blast my music from my cell through my car stereo without any extra accessories or wires!