base_convert (md5($something), 16, 36);
на 21,88% круче, чем
md5($something);
Discuss!
Update:
На 31,25% круче:
$test = trim (base64_encode (md5 ($something, true)),"==");
или (php<5)
$test = trim (pack ("H*", base64_encode (md5 ($something))),"==");
И обратно:
$test = unpack ("H*", base64_decode ($test."==")); $test=$test[1];