A tin can phone that plugs into your computer, cellphone or tablet- and works! Yes, you can actually talk to people with it- we keep calling our friends.
This is a project found on KickStarter that has an interesting view on mobile communication. they are still quite a bit away from raising the required funds, but I do like the idea enough to make a mention.
Since an image speaks more than a thousand words…
more on their Kickstarter page or in this wired article.