The most spectacular applications are found within the industrial sector where the laser is used as a tool for cutting and welding. When welding seams with high accuracy and smooth metal surfaces are required, the solution is laser machining. There are some problems though, since some metals reflect the laserlight which is why high power (and expensive) lasers could be necessary. Lasers with an optical power of 5kW aren't unusual!
Laser cutting saves material because the beam cuts a narrow kerf without ruining lots of valuable metal, as in the case with other mechanical cutting methods. For instance titanium is commonly cut with a laser, because this metal is very expensive and also very hard, which makes mechanical tools blunt. The laser, though, doesn't get blunt.
Making holes
The laser is also a good tool for making small holes in, for example, diamonds, which could take several days with ordinary drilling. With a pulsed CO2-laser it will only take a couple of seconds. Lasers are also very good at making small holes, less than tenths of a millimetre, where ordinary drilling obviously is more complicated.
The drawback is that in some materials the holes are conical, because the beam is focused with a lens and thereby conical. Also bi-products and oxides could cause problems when drilling at low laser-power. When higher power is used, for example with metals, the temperatures are often so high that the material totally goes into vapour.
Lasers are also used in more ordinary applications than you think; they are used to make the holes in aerosol spray cans, and also in softer materials such as rubber and paper are processed with lasers. The hole in the nipple of the baby-bottle is made with a laser and so are the small holes (diam. 0.25 mm) in cigarette paper that is supposed to regulate the tobacco-combustion so that it has a low concentration of tar.
An application that is rising in interest is laser welding. If the beam is focused a little bit above the surface, and also has an atmosphere of protective, inert gas at the welding spot instead of oxygen that is used in cutting, the material will melt without oxides. The materials can be joined together almost like in TIG-welding, but with less heat-affection.
Hardening
It's also possible to harden a surface by pointing an unfocused laser beam onto the material that will heat the material rapidly and then the material will be hardened during the cooling process.
An interesting application is to put a protective layer of hardened material on a tool. This is in practise achieved by blowing in metal powder into the laser beam. The powder will be heated and be vaporized without being oxidized (a protective gas is used). The metal-gas hits the surface of the tool and it will condense at the same time as the heat from the beam will harden the surface. This will increase the life of the tool by about four times.