Func<string, string> ReverseString = delegate(string s)
{
    char[] word = s.ToCharArray();
    for (int i = 0, j = (s.Length - 1); i < j; i++, j--)
    {
        char _temp = word[i];
        word[i] = s[j];
        word[j] = _temp;
    }

    return new string(word);
};                
//csharp/6446