RepStrap is 3d printer made from any parts available. They have raw DIY appeal and some of them are masterful DIY devices that would make MacGyver envious. Low cost of RepStraps is another advantage. They are not the most beautiful machines and noise level seems high ... but hey ... it's another type of cool ..
RepRap wiki with more details:
WolfStrap RepStrap with build details:
Youtube user: http://www.youtube.com/user/MongrelShark?feature=watch has documented build process for his RepStrap, here is first video in the series: