Asynchronous Conversations

Idea:
Enable people to carry on spoken conversations in an asynchronous fashion.

Details:
The concept isn't too far out there - really its similar to email. As in, I write you and email and at some point in the future (not virtually instantaneously) you read it and potentially respond to it. Why not do the same thing with the spoken word?

I believe the scenario would look like this:
1) I have a number of topics that I want to talk to you about. I make a voice recording of topic one (i.e., I speak into my iPhone to the aSynch application). After the first topic area, I tap "end topic" and then begin talking about the next one.
2) I synchronize my conversation with a asynchronous conversation website (ACW). While doing so, I add a text tag to describe any new topics that I've brought up. Perhaps its a new service of Skype (although it doesn't seem to fit their mold).
3) My friend then synchronizes to the ACW, and my portion of the conversation is downloaded to his device (perhaps a Blackberry, but in any event, the only requirement would be that it was "standards compliant").
4) My friend looks at the topic areas (remember, all have been tagged), and arranges them in order that s/he wants to listen to them (or leaves them in the default order). Also, he decides how he wants to listen to the topics (her/his previous comments, then my responses; or just my responses).
5) My friend listens to my side of the conversation and at the end of each topic, they are prompted to add their response. Alternatively, they can break into the conversation and respond with something; useful if you are afraid that you'll forget about a specific point that you wanted to make.
6) The cycle of synchronizing and responding continues.

Interface
I think that this idea, while intriguing, is a real challenge from an interface standpoint. It will have to be very easy and intuitive to listen and respond. Ideally, it would be as intuitive as having a face-to-face conversation. It can't be that, but it can strive to be as close as possible.

Will it Work?
With the caveat of the above paragraph, I think that it absolutely could work, but there are a whole host of challenges:
1) Hardware: you don't want to have a dedicated piece of hardware to make this work, it has to be integrated into existing devices. As much as smartphones are doing something very similar, they seem like obvious devices to build software around.
2) [More to Come]