There are many alternative ways of adding an element onto the end of an array, none of which are as easy to read as push, although that is, of course, subjective. Many are considerably slower than push and some are just plain daft:

push(@array, 'ree');
$array[$#array+1] = 'ree';
$array[@array]    = 'ree';
splice(@array,@array,0,'ree');
@array=(@array,'ree');
[download]

I'm fairly sure there are a couple more.