Optimus S - Can't change voicemail provider to Google Voice
In my prior experience with Android phones, when you setup Google Voice, it offers to change your default voicemail provider. It would send you to the Settings -> Call Settings page. Normally, you'd have a "Voicemail Service" option to select a different voicemail service than Sprint's default. Here I'd select Google Voice.
Unfortunately, the option is blocked or missing on my LG Optimus S. I'd like to see this fixed in a maintenance update.