I think he's talking about how the Iphone has a screen that downloads the voicemail to the phone and play without calling your voicemail. Its called Visual Voicemail. see link for example:
http://support.apple.com/kb/HT1486 .
There is a different way to get voicemail... voice to text.
PhoneTag (
http://phonetag.com/index.html) automatically converts your voicemail into text and delivers it directly to your mobile phone. Bad news...its a paid service.