i recently started using a service called phonetag to transcribe and email me all of my voicemail. i always hated receiving voicemail, and phonetag is an amazing service.
one thing has started to happen which i think is worth noting. specifically, because information is being input via voice and output via text some of the meta-data of a call is getting lost in the transfer. people have come to rely on caller id and the sound of their own voice to identify themselves to eachother. no need to announce that 'this is your father' - you know my voice. transcription services mess with this, and people leave you messages that without the context of caller id built in or voice are harder to understand/know who is calling.
in fairness to phonetag, which i very much like, they know this and send you an mp3 of the call along with the transcription (so you can always figure it out if you have to) -- but it is interesting to watch mediums of communications shift and, as a result, people needing to consider what metadata is automatically encoded in their message, and what needs to be made explicit based on where the information will ultimately be consumed.