If you search for Martin Jetpack, you might see videos of it since 2008. After so many years, Martin seems confident enough to announce that the Martin Jetpack might be available in 18 months.
However, it is sad to see that they are using graphics rendered video to showcase the usage of the Jetpack. In short, they are not ready to show the real thing (although you can see many of the flights in Youtube). Here is the video.