Sorry for being so late to this party.
And...there may be a hidden way to do this in the modeling toolkit that I am not aware of. There is lots in Maya that is hidden...
But for faces, what could be done is you could select a loop of faces then run the following:
source getFaces;
string $selectedFaces[] = `getFaces`;
int $x;
for($x = 0; $x < size($selectedFaces); $x++){
if( ($x % 2) == 0 ){
select -deselect $selectedFaces[$x];
}
}
^ the above code could be added to the shelf.
to invert, just hold down shift and select the currently selected faces and it will select the unselected faces and deselect the currently selected faces.
