Voicemail

I know we all tried to call people a lot to find out they aren't in the city, or downed, or just busy.
Having a voicemail would be amazing. But I know recording someones voice would be tough. I think it would be cool after so man rings you have a text box pop up to leave a "Voicemail" It would be a text message that sits in a separate text box waiting to be read by the person you tried to contact