Is it safe to try this setup on my DSLR(since there will be no lens), mine is Canon EOS 1000D?
It is possible to make a pinhole from a DSLR. Basically, buy a spare body cap, then make a small hole in its center. Don't destroy the only cap which comes with your camera, you may need it later. Google for "DIY DSLR pinhole" for multiple instructions.
But you should remember that it is still a hole, not a glass, so some dust or liquids may come through it into the camera. On the other hand, when you change lens, even larger quantities of dust may come in.
Dust on the mirror or even on the sensor is not dangerous, but you need to be careful when you clean it later. Dust on the mirror does not affect the quality of the image, but it is visible in the viewfinder, and sooner or later it may reach the sensor. The dust on the sensor is not visible in the viewfinder, but it is visible on the shots with small aperture (large f-number) and, surprise, on pinhole shots. You should not touch the mirror when you clean it, it can be easily scratched; use only a special photographic air bulb to clean it. To clean the sensor you'll need to buy special cleaning kits and have enough patience, but sometimes the air bulb is enough. Sooner or later all photographers have to do it.
Has anyone tried it and got interesting result ?
There is a whole group on Flickr dedicated to Digital Pinhole Photography
An alternative design: a pinhole box.
They also suggest an alternative digital pinhole design in the group description. It is safer, because doesn't require to open the camera and is compatible also with compact cameras:
A ready to use pinhole
If you want to spend some money, you may buy a ready to use pinhole (f/177) from Lensbaby (you'll need to acquire their adapter too) or from other producers (see answers from @Jay Lance Photography and @Stan Rogers).