Is there a way to loop through the elements in an enum (foreach or for loop)?

Consider the following enum:

private enum myEnum
{
	one,
	two,
	three,
	four
}

I know the enum can be looped like this but I have to hardcode the loop termination:

string s = "";
for (int i = 0 ; i < 4 ; i++)
{
	s += ((GlobalCategories)i).ToString();
}
MessageBox.Show(s);

Thanks,
Einar