I have not quite figured this out yet for multiline/word variables or arrays, but to pass a single word argument, just do something like:
#php -q myphpscript.php arg1 arg2 ...
The script myphpscript.php will receive an array of values (argv[]) that can then be read into variables of your choosing, such as:
$firstvar = argv[1];
$secondvar = argv[2];
and so on.
If anyone has figured out how to pass text or arrays, let me know. I suspect it requires a pipe of some sort, by I haven't found any syntax for that yet.