This DIY video camera dolly is made of inexpensive PVC pipes and rollerblade wheels (from a discount store). For under $US20, you can build your own dolly to get smooth rolling video shots.
The dolly doesn't take long to build and requires only basic hardware skills. As the video shows, there are quite a few applications for this, such as low-angle shots or just to keep the camera steady while filming a subject. (After viewing the samples, you might want to become a videographer if you aren't one already.)