You can choose your own photos or one of the millions you can find over internet. Remember to choose a high quality one in order to make a better poster with no problems.
Poster Forge is a free application that allows you to create a poster from any photo and add some letters, phrases or even choose the frames and effects.
Choose the kind of poster you want to create: Standard, movie or wanted, like the ones of western movies. It's easy, just follow the simple steps suggested by the intuitive interface and you'll have your own custom poster in less than one minute.