How to get all subsets of an array?

Elegant? Why not Linq it.

    public static IEnumerable<IEnumerable<T>> SubSetsOf<T>(IEnumerable<T> source)
    {
        if (!source.Any())
            return Enumerable.Repeat(Enumerable.Empty<T>(), 1);

        var element = source.Take(1);

        var haveNots = SubSetsOf(source.Skip(1));
        var haves = haveNots.Select(set => element.Concat(set));

        return haves.Concat(haveNots);
    }

 string[] source = new string[] { "dog", "cat", "mouse" };
 for (int i = 0; i < Math.Pow(2, source.Length); i++)
 {
     string[] combination = new string[source.Length];
     for (int j = 0; j < source.Length; j++)
     {
         if ((i & (1 << (source.Length - j - 1))) != 0)
         {
             combination[j] = source[j];
         }
    }
    Console.WriteLine("[{0}, {1}, {2}]", combination[0], combination[1], combination[2]);
}