> A method belongs to one and only one class, doesn't it?
>

Except, perhaps, when your are dealing with extension methods

Here's one that applies to all classes

public static partial class ExtensionMethods
{
        static public string MyToString<T>(this T s)
	{
		return "<" + s.ToString() + ">";
	}
		
}

or

public static partial class ExtensionMethods
{
        static public string MyToString(this object s)
	{
		return "<" + s.ToString() + ">";
	}
		
}

Here's one that applies to all classes which implement IEquatable< T >

public static partial class ExtensionMethods
{
     public static bool InList<T>(this T s, params T[] list) where T : IEquatable<T>
		{
			return list.Contains(s);
		}		
}