There finally appears to be an affordable product (http://www.emotiv.com/) designed to recognize your mood, simple intentions etc. basing on the analysis of the readings from a futuristic looking device worn on your head and capturing EEG data (14 channels).
However farfetched this sounds, it is potentially possible although it is hard to tell how accurate, fast and practical it will be. I guess the situation now can be compared to the dawn of speech recognition. In the case of the speech recognition there are 6 billons of live proofs that it is doable, but it took quite a while to perfect it to the levels of accuracy when it finally became practical. In the case of EEG recognition, it is just the scientific experiments and no use in the “field” so far.
In any case it is very exciting to see an affordable commercial product like that. My attempt to experiment with EEG pattern recognition a few years back stalled as the only reasonable option I found at that time was http://www.ant-neuro.com/products/asa-lab, which targets research institutions and is priced accordingly. The Emotion product opens new grounds for curious minds…