LG enV VX-9900
Changing it from digital only hybrid to 1x only....
I think that just turns off EV-DO high-speed data... which the only reason I could see for doing that is if you were using DUN and didn't want to get caught... but if you're not using Dial-Up on your phone... I wouldn't... its just going to make downloads slower...
Correct me if I'm wrong... hope that helps..