If you want to bring a projector in your pocket (or your bag) for use with your iPod or iPhone, than this Lancerlink iJector, an LCOS projector. Shaped like a dock, the device makes it possible to watch video stored on your iPod on the go via its built-on stereo speakers (3W×2ch).
The iJector weighs just 120g and measures 195×145×96mm. It produces images sized up to 50 inches from 2.3m away and features a resolution of 557×234 pixels, which is quite low. The projector also features 20 lumens brightness and comes with a lamp that has a life span of 30,000 hours.

The iJector is compatible with the following:

iPod nano generation 1
iPod nano generation 2
iPod nano generation 3
iPod video generation 5 30 GB
iPod video generation 5 50 GB
iPod Classic 80GB
iPod Classic 160GB
iPod touch 8GB
iPod touch 16GB
iPod touch 32GB
iPhone 3.0

The iJector is licensed by Apple and costs $700 in Japan. It looks like it will be available in Japan only, on July 17. Sound like a lot of money and there are alternatives.

Source: Crunchgear