Today I have baked latest image (containing ruby, pcapsipdump, asterisk, silk codec).
Because it is still a bit alpha, I was created shorted URL, download link, containing latest image: [j.mp/tinypbx](//j.mp/tinypbx).
Standard flashing instructions: gunzip .gz file, insert SD card, flash with Linux DD command... [This site](http://www.andrewmunsell.com/blog/getting-started-raspberry-pi-install-raspbian/) for example, describing flashing procedure well.
[GIT repository with script](https://github.com/andrius/build-raspbian-image), which creates RPI images, was updated and I will create separate post describing it. In few words: installer creates minimal raspbian image, at the end, mounts folder "delivery" to the target image and executes bash script "install.sh" (you find sample in GIT repository).