could you please tell me how I can make a ring of holes into the cap end of a cylinder? The end of the cylinder should look like a mouthpiece of an old telefone. The holes shall not be flat but more like little cylinders without cap ends.
Rectangular hole can be turned into circular hole with Subsurf modifier. It is really a quick way to create holes. Here is the example; some tweaking required to make it a real round hole.