Anagram finder in C# (Mono)

anagram_mono.cs

public static void Main (string[] args)
{
    var words = System.IO.File.ReadAllLines("/usr/share/dict/words");
    var anagramLookup = words.ToLookup(MakeAnagramKey);

    var anagrams = anagramLookup[MakeAnagramKey("pots")];

    Console.WriteLine(string.Join(Environment.NewLine, anagrams.ToArray()));
}

static string MakeAnagramKey (string w)
{
    return new string(w.OrderBy(c => c).ToArray());
}