There are a surprising number of services that do this. No one seems to have gotten any traction though. We decided to make it a video service instead of an email service.

We're actually launching our version this friday. If you read this after Aug 19th, it will be at http://senotable.com but right now it's at http://beta.senotable.com. Bugs are basically worked out now if you want to check it out. We'll probably advertise the launch on HN Saturday.