Google Voice Call Screening and the iPhone

If you have Call Screening active, and you answer a call from your Google Voice forwarding number, you must press "1" in order to answer the call (or otherwise navigate a touch-tone menu system). Don't know about you, but I find this to be a minor but annoying inconvenience.

You can turn off Call Screening, but there are two sides to every Schwarz, and while the call will now connect with no confirmation required, your phone's voicemail will engage before Google voicemail--thus losing all those neat Google voicemail advantages.

But have no fear; there is a solution. Just extend your phone's voicemail timeout to be of a longer duration than the Google voicemail timeout, thereby ensuring an unanswered call is always sent to Google Voice's voicemail system before it reaches your provider's voicemail system.

In other words:
http://support.google.com/voice/bin/answer.py?hl=en&topic=19490&answer=115110

Now I can't speak for other carriers and phone models, but in order to set the voicemail timeout for an AT&T iPhone 4, the following instructions worked fine for me (source):

1. Dial "*#61*".
2. Copy down the number in the text "Voice Call Forwarding When Unanswered Forwards to +1XXXXXXXXXX Enabled"
3. Dial *61*+1XXXXXXXXXX*11*tt# where +1XXXXXXXXXX is the number you copied in the previous step, and "tt" is the number of seconds (from 5 to 30 in increments of 5) for the voicemail timeout duration you wish.

As the Google Voice timeout is 25 seconds, I recommend setting your carrier timeout to 30 seconds.

Update: There's this, too.