{Please|Just} make this {cool|awesome|random with {my|good}} test sentence
{rotate {quickly|fast} and random|spin and be random}

<?php
$text='{Please|Just} make this {cool|awesome|random with {my|good}} test sentence
{rotate {quickly|fast} and random|spin and be random}';
$flag=true;

while($flag) {
	$flag=false;
	$text=preg_replace_callback('#{[^{}]*}#', 'Handler', $text);
}

function Handler($m) {
	global $flag;
	$a=explode('|', substr($m[0], 1, -1));
	$flag=true;
	return $a[rand(0, count($a)-1)];
}

echo($text);

?>

1.(jetistyum) 5.3, 6.4  
2.(max) 13.6, 15.0  
3.(zarafar) 3.1, 4.7  
4.(glock18)
вариант 2: 2.37, 3.44  
вариант 3: 3.25, ---  
5.(Michael) 2.32, 2.14 
6.(Семён) 1.7, 2.53 
7.(gzim9x) 
вариант 1: 2.10, 3.10 
вариант 2: 1.65, 2.42 

<?php
function randomSentence($string) {
    preg_match_all("/\{[^{}]+\}/", $string, $out);
    if (isset($out[0][0])) {
	for ($i=0,$l=sizeof($out[0]);$i<$l;$i++) {
	    $__a=explode('|',str_replace(array('{','}'),array('',''),$out[0][$i]));
	    shuffle($__a);
	    $string=str_replace($out[0][$i],$__a[0],$string);
	}
	return randomSentence($string);
    }  
    return $string;
}

print randomSentence('{Please|Just} make this {cool|awesome|random} test sentence {rotate {quickly|fast} and random|spin and be random}');
?>

function randomSentence($string) {
    return (strpos($string,'{')===false) 
        ? $string
        : call_user_func(__FUNCTION__, 
			 preg_replace_callback("/{[^{}]+\}/i", 
					       function($out) { 
						   return $a[array_rand($a=explode('|', trim($out[0],'{}')))];
					       }, 
                                               $string));
}
print randomSentence('{Please|Just} make this {cool|awesome|random} test sentence {rotate {quickly|fast} and random|spin and be random}');

$text = '...';

function getRnd($arr) {
     return stripslashes($arr[array_rand($arr, 1)]);
}
echo preg_replace('/{(.+?)}/es', "getRnd(explode('|', '$1'))", $text);

function call($out) {
    return $a[array_rand($a=explode('|', trim($out[0],'{}')))];
}
function randomSentence($string) {
    return (strpos($string,'{')===false) 
        ? $string
        : call_user_func(__FUNCTION__, preg_replace_callback("/{[^{}]+\}/i",'call',$string));
}
print randomSentence('{Please|Just} make this {cool|awesome|random} test sentence {rotate {quickly|fast} and random|spin and be random}');

function randomSentence($string) {
    return (strpos($string,'{')===false)
        ? $string
        : ((strpos($string, '}') === false)
            ? exit('Syntax error!')
            : call_user_func(__FUNCTION__, preg_replace_callback("/{[^{}]+\}/",'call',$string)));
}

<?php
    error_reporting(E_ALL);
    session_start();
    header("Content-Type: text/html; charset=utf-8");

/**
 * Functions
 */

function show($text2,$temp,$soul)
{
    $result = $text2;
    foreach($temp as $k => $v)
    {
        $result = str_replace('$array['.$k.']',$temp[$k][$soul[$k]],$result);
    }
    return $result;
}

function improve(&$soul,$count,$howmuch)
{
    $soul[0] = 0;
    $num = 1;
    while(true)
    {
        if($num > $count)
            return false;
        if(++$soul[$num] <= $howmuch[$num] -1)
        {
            break;
        }
        else
        {
            $soul[$num++] = 0;
        }
    }
    return $soul;
}

function makeText($tpl,$text,$delete)
{
    $text2 = $text;
    preg_match_all("/\{.{1}(?:[^\{]{1})+?\}/ius",$text,$matches);

    $num = 0;
    foreach($matches[0] as $k => $v)
    {
        $text2 = str_replace($v,'$array['.$num++.']',$text2);
        $temp[$k] = explode('|',str_replace($delete,'',$v));
        $howmuch[$k] = count($temp[$k]);
        $soul[] = 0; 
    }

    $count = count($soul)-1;
    while(true)
    {
        if($soul[0] == 0)
        {
            $tpl[] = show($text2,$temp,$soul);
        }
        if(++$soul[0] <= $howmuch[0] - 1)
        {
            $tpl[] = show($text2,$temp,$soul);
            continue;
        }
        else
        {
            if(!improve($soul,$count,$howmuch))
                break;
        }
    }
	return $tpl;
}

/**
 * Starting text
 */

$text = "{Пожалуйста|Просто} сделайте {так чтобы|чтобы} это {удивительное|крутое|простое} тестовое {a|{b|{c|d}}} предложение {изменялось {быстро|мгновенно} случайным образом|менялось каждый раз}.";
echo $text;
$delete = array('{','}');
$tpl = array();

/**
 * Controller
 */

//Первая вложенность
$text = makeText($tpl,$text,$delete);

//Вторая вложенность
foreach($text as $v)
	$text3[] = makeText($tpl,$v,$delete);

//Третья вложенность
foreach($text3 as $value)
    foreach($value as $v)
        $text5[] = makeText($tpl,$v,$delete);

/**
 * VIEW
 */

echo '<pre>';	
print_r($text5);

<?php

    $rand_sentence = '{Please|Just} make this {cool|awesome|random} test sentence
        		     {rotate {quickly|fast} and random|spin and be random}';
    do
    {
        preg_match_all('#\{((?>[^{}]+)*)\}#', $rand_sentence, $out);

        foreach ($out[1] as &$val)
        {
            $val = explode('|', $val);
            $val = $val[rand(0, count($val)-1)];
        }

        $rand_sentence = str_replace($out[0], $out[1], $rand_sentence);
    }

    while (count($out[0]) != 0);
    echo $rand_sentence;

$rand_sentence = "{Please|Just} make this {cool|awesome|random} test sentence {rotate {quickly|fast} and random|spin and be random}";

$regexp = '#\{((?>[^{}]+)*)\}#';

while(strpos($rand_sentence, '{') !== false)
	$rand_sentence = preg_replace_callback($regexp, 'replace_match_str', $rand_sentence);

echo $rand_sentence . "\n"; 


function replace_match_str($str)
{
	$result = explode("|", $str[1]); // split string by "|" symbol
	$replacement = array_rand($result); // random array ellement

	return $result[$replacement];
}