Here is the wort chiller I use.  I did not make it myself, but it seems to be an example of the basic, cheap, easy-to-make immersion chiller.

The plastic tubing this one has is about 4 feet long.

This is the type of clamp it has, but I'm sure anything that would do the same thing would work, like those screw down ones that are similar to this.  The plastic tubing goes over the copper. 

There is a little corrosion visible but the wort never touches that part.   The coils that the wort touches are sanitized at the end of the boil, and I clean the chiller off well after using it.

This screws on to my laundry tub sink.  I think it is the same fitting that will also screw onto a garden hose.

This gives you can idea as to how the tubing is bent at the bottom and top.