If you can't play the video, don't be sad. Take a look at it here...
Easily print your own postersdesign 60 times in a jiffy. Design and make your own wallpaper. Or customize t-shirts, bags and curtains using textile paint. Or... or... or... If you make a roller stamp yourself, please post a pic of the results!
The trick is to use a rolling pin as a roller, and pieces of inner tube as stamp rubber. Roller pins are really cheap, and available in various sizes (Ikea sells them in different sizes, their biggest model is 43 cm wide and costs €2,49 / $3,06). Used inner tubes are for free at your local bike shop (at least in The Netherlands. Bike shops here don't have a use for worn inner tubes. Tsssssskkk.....).
The making of the roller stamp itself is as easy as it gets. So invest your talent and time in making a good design and cutting it out of an inner tube.