Here's a lovely animated GIF, taken from @ryanlawler's coverage:
Talko's been in development for over 2 years (which seems like an eternity in internet years). I just took it for a quick run and it seems very polished, certainly more feature rich than most voice communication apps on day 1. Although I love the scan-ability and asynchronous nature of text, it's much slower and carries less emotion than speech.
I need to play with this a bit before I can formulate much of an opinion.
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