Olaf Diegel has created a very cool printing project that is specifically designed to be printable on almost every type of printer. Anyone looking for an original robotic printing project should definitely check out his Oddbot.
Face Detection and Tracking With Arduino and OpenCV
If you hate vacuuming as much as you hate spending money, it turns out you don’t need to spend hundreds of dollars on an autonomous robotic vacuum like the Roomba. With some scavenged electronics and a cheap handheld vac, you can just build your own.