when I develop apps, I tend to add more and more arguments
to my functions giving them default values for backward
compatibility. but as soon as your function has more than
14 arguments :) it gets very tiring to write them all...

it would be great if you could specify WHICH arguments you
want to pass to the function... like:

function foo($arg1, $arg2 = 0, $arg3 = "none")
{
  ...
}

foo("wow", $arg3 => "bar");