Hi Laurie,

I have searched many forums and read hundereds of lines of code and finally built a script that works for this task.

The task is to select each and every poly face that faces the x axis only,
The useful purpose for this is to select all x facing poly faces of a structural mesh like a house and uv project in that axis. Once you have the x axis projected you can manually invert your selection and project for the z axis very easily, and the y axis is a breeze.

I am new to mel so please excuse the amature code:

//__________________________________________________ ______________________________________________
//Select all the X facing faces of a poly mesh selection
//created by: bikehawk
//date: 08-03-2011

//------------------------------------------------------
//Select one poly mesh
select -r pCube1 ;
//list the selection
string $selection[] = `ls -sl`;
print $selection;

//Select all the faces of an object
select -r $selection.f["*"];

//add a line
print ("\n");

//now get and display the individual number of faces in the selection
string $faceList[] = `filterExpand -sm 34`;

print $faceList;

//add a line
print ("\n");

//declare a variable with the number of faces
$nof = (size($faceList));

//variable to loop the for loop the correct amount of times
$nofLoop = $nof - 1;

//print the number of faces
print ("Num of faces is: " + $nof + "\n");

//select the cube to clear the face selection
select -r pCube1 ;

//Start the FOR LOOP*************************
for ($i=0;$i<=$nofLoop;$i=$i+1)
{
print $faceList[$i];
print ("\n");

//get all the face normal vectors
string $polyInfo[] = `polyInfo -faceNormals $faceList`;

//specify 1 face normal vector
$polyInfo = stringToStringArray($polyInfo[$i]," ");

//put vectors into variables
float $vPosX = $polyInfo[2];
float $vPosY = $polyInfo[3];
float $vPosZ = $polyInfo[4];

if ($vPosX >= 0.5)
{

print ("Select this face: " + $faceList[$i]);
select -tgl ($faceList[$i]);
}
if ($vPosX <= -0.5)
{
print ("Select this face: " + $faceList[$i]);
select -tgl ($faceList[$i]);
}

//add a line
print "\n";

}
//end the FOR LOOP*************************

//------------------------------------------------------

Hope this helps a few people, and any comments or code cleanup are very welcome.
Cheers guys