Plover: Thought to Text at 240 WPM

No, this isn't a mind reading device. It's an open-source, chording stenography system. Instead of hitting individual keys for individual letters, you hit chords or keys, and that gets mapped to the text you (hopefully!) want.

The result is many, many fewer actions to get the same amount of text, allowing higher output speeds.

Only works on some keyboards, and there are some workarounds for some of the keyboards that don't fully support chording..

No links at the YouTube page. I found this neat in-browser demo though: http://stenoknight.com/kws.html

There are cheap steno machines, with the proper key layout, for less than 50 on ebay.