Function to return only the files in a directory, and optionally do this recursively.

getFilesInDirectoryAsArray.php

<?php
function getFilesInDirectoryAsArray($directory, $recursive, $arrFilter=array()) {
    $arrItems = array();
	if(substr($directory, strlen($directory)-1, 1) != "/"){
		$directory.="/";
	}
	if(count($arrFilter)){
		$filterMap=array();
		for($i=0;$i<count($arrFilter);$i++){
			$filterMap[$arrFilter[$i]]=true;
		}
		var_dump($filterMap);
		recurseDirectoryWithFilter($arrItems, $directory, $recursive, $filterMap);
	}else{
		recurseDirectory($arrItems, $directory, $recursive);
	}
    return $arrItems;
}
function recurseDirectory(&$arrItems, $directory, $recursive) {
	if ($handle = opendir($directory)) {
		while (false !== ($file = readdir($handle))) {
			if ($file != "." && $file != "..") {
				if(is_dir($directory.$file)) {
					if($recursive){
						recurseDirectory($arrItems, $directory.$file."/", $recursive);
					}
				}else{
					$arrItems[] = $directory . $file;
				}
			}
		}
		closedir($handle);
	}
    return $arrItems;
}
function recurseDirectoryWithFilter(&$arrItems, $directory, $recursive, &$filterMap) {
	if ($handle = opendir($directory)) {
		while (false !== ($file = readdir($handle))) {
			if ($file != "." && $file != "..") {
				if(is_dir($directory.$file)) {
					if($recursive){
						recurseDirectoryWithFilter($arrItems, $directory.$file."/", $recursive, $filterMap);
					}
				}else{
					if(isset($filterMap[getFileExt($file)])){
						$arrItems[] = $directory . $file;
					}
				}
			}
		}
		closedir($handle);
	}
    return $arrItems;
}
function getFileExt($path){
	$pos=strrpos($path, ".");
	if($pos===FALSE){
		return "";
	}else{
		return substr($path, $pos+1);
	}
}
?>

Use like this: var_dump(getFilesInDirectoryAsArray("/path/",true));

Added support to filter the files by one or more file extensions. Usage: var_dump(getFilesInDirectoryAsArray("/path/",true, array("js", "css")));