When uploading multiple files, the $_FILES variable is created in the form:

Array
(
    [name] => Array
        (
            [0] => foo.txt
            [1] => bar.txt
        )

    [type] => Array
        (
            [0] => text/plain
            [1] => text/plain
        )

    [tmp_name] => Array
        (
            [0] => /tmp/phpYzdqkD
            [1] => /tmp/phpeEwEWG
        )

    [error] => Array
        (
            [0] => 0
            [1] => 0
        )

    [size] => Array
        (
            [0] => 123
            [1] => 456
        )
)

I found it made for a little cleaner code if I had the uploaded files array in the form

Array
(
    [0] => Array
        (
            [name] => foo.txt
            [type] => text/plain
            [tmp_name] => /tmp/phpYzdqkD
            [error] => 0
            [size] => 123
        )

    [1] => Array
        (
            [name] => bar.txt
            [type] => text/plain
            [tmp_name] => /tmp/phpeEwEWG
            [error] => 0
            [size] => 456
        )
)

I wrote a quick function that would convert the $_FILES array to the cleaner (IMHO) array.

<?php

function reArrayFiles(&$file_post) {

    $file_ary = array();
    $file_count = count($file_post['name']);
    $file_keys = array_keys($file_post);

    for ($i=0; $i<$file_count; $i++) {
        foreach ($file_keys as $key) {
            $file_ary[$i][$key] = $file_post[$key][$i];
        }
    }

    return $file_ary;
}

?>

Now I can do the following:

<?php

if ($_FILES['upload']) {
    $file_ary = reArrayFiles($_FILES['ufile']);

    foreach ($file_ary as $file) {
        print 'File Name: ' . $file['name'];
        print 'File Type: ' . $file['type'];
        print 'File Size: ' . $file['size'];
    }
}

?>

A bit update to 14 year ago note from "phpuser at gmail dot com".
That update converts to a really more friendly array form incoming _POST info for uploaded files. 
And that variants works identical for non-multiple uploads and multiple uploads:
<?php
//Функция переформатирует массив поданных POST'ом файлов
function reArrayFiles(&$file_post){
    $isMulti    = is_array($file_post['name']);
    $file_count    = $isMulti?count($file_post['name']):1;
    $file_keys    = array_keys($file_post);

    $file_ary    = [];    //Итоговый массив
    for($i=0; $i<$file_count; $i++)
        foreach($file_keys as $key)
            if($isMulti)
                $file_ary[$i][$key] = $file_post[$key][$i];
            else
                $file_ary[$i][$key]    = $file_post[$key];

    return $file_ary;
}
?>

This is also needed for <input type=file multiple> elements.

So, if you have an input element like this:
<input type="file" multiple="multiple" name="foobar" />
This should be written as
<input type="file" multiple="multiple" name="foobar[]" />
else you'll only be able to get one of the files.

Here is a function to fix the indices of a multi-dimensional for easier parsing when dealing with file uploads.  It takes a single $_FILES field array as a parameter and separates each individual uploaded file by numeric key.  This allows for iterating like:

<?php
fixFilesArray($_FILES['array_of_files']);
foreach ($_FILES['array_of_files'] as $position => $file) {
    // should output array with indices name, type, tmp_name, error, size
    var_dump($file);
}
?>

Here's the code:

<?php
/**
 * Fixes the odd indexing of multiple file uploads from the format:
 *
 * $_FILES['field']['key']['index']
 *
 * To the more standard and appropriate:
 *
 * $_FILES['field']['index']['key']
 *
 * @param array $files
 * @author Corey Ballou
 * @link http://www.jqueryin.com
 */
function fixFilesArray(&$files)
{
    $names = array( 'name' => 1, 'type' => 1, 'tmp_name' => 1, 'error' => 1, 'size' => 1);

    foreach ($files as $key => $part) {
        // only deal with valid keys and multiple files
        $key = (string) $key;
        if (isset($names[$key]) && is_array($part)) {
            foreach ($part as $position => $value) {
                $files[$position][$key] = $value;
            }
            // remove old key reference
            unset($files[$key]);
        }
    }
}
?>

The cleanest way to rearrange the $_FILES

<?php
function rearrange( $arr ){
    foreach( $arr as $key => $all ){
        foreach( $all as $i => $val ){
            $new[$i][$key] = $val;    
        }    
    }
    return $new;
}
?>

This is a very simple example:

Part I : HTML

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <form action="upload.php" method="post" multipart="" enctype="multipart/form-data">
        <input type="file" name="img[]" multiple>
        <input type="submit">
    </form>
</body>
</html>

Part II : PHP

<?php
echo '<pre>';
$img = $_FILES['img'];

if(!empty($img))
{
    $img_desc = reArrayFiles($img);
    print_r($img_desc);
    
    foreach($img_desc as $val)
    {
        $newname = date('YmdHis',time()).mt_rand().'.jpg';
        move_uploaded_file($val['tmp_name'],'./uploads/'.$newname);
    }
}

function reArrayFiles($file)
{
    $file_ary = array();
    $file_count = count($file['name']);
    $file_key = array_keys($file);
    
    for($i=0;$i<$file_count;$i++)
    {
        foreach($file_key as $val)
        {
            $file_ary[$i][$val] = $file[$val][$i];
        }
    }
    return $file_ary;
}

Just combine temporary path with the filename which will result an array like:

array(2) {
  ["/tmp/phpAYCvcc"]=> string(10) "file1.jpg"
  ["/tmp/phpCDg79o"]=> string(10) "file2.jpg"
}

The code:

$files = array_combine(
     $_FILES['receipt']['tmp_name'], 
     $_FILES['receipt']['name']
);

foreach ($files as $key => $value) {
    // save your files locally
}

function reArrayImages($file_post) {
    $file_ary = [];
    $file_keys = array_keys($file_post);
    foreach ($file_post as $key => $value) {
      foreach ($value as $key2 => $value2) {
        $file_ary[$key2][$key] = $value2;
      }
    }
    return $file_ary;
}