It is not the first application of this kind for iPhone/iPod Touch, but this "promises" more than the previous one - TV Out-, both are free in Cydia. Through the audio-video cable you can transmit the images from the phone screen directly to the TV screen, fullscreen and as this application boasts in landscape mode thanks to it and even at a decent FPS.
I've never tried the AV cable method, never even thought of it, but has anyone tried it? how is the quality Does it move decently or is it a slideshow of pictures on the monitor?
