UPDATE: The screenshot below was lost to the big /dev/null in a server move, so you have to use your imagination.

Can you make a property in C# that you can only add to and remove from? That is what an event does, but that only works with delegates. You can (ab)use an implicit conversion to get something like this:
[code lang="csharp"]

class Foo
{
public delegate void FooDelegate();
public string Message { get; set; }

public Foo(string message)
{
Message = message;
}

public static implicit operator FooDelegate(Foo foo)
{
return foo.Dummy;
}

private void Dummy() { }
}

class Bar
{
public List FooList { get; private set; }

public event Foo.FooDelegate Foos
{
add
{
FooList.Add((Foo)value.Target);
}
remove
{
FooList.Remove((Foo)value.Target);
}
}

public Bar()
{
FooList = new List();
}
}[/code]
Using it:
[code lang="csharp"]
static void Main(string[] args)
{
Bar bar = new Bar();
bar.Foos += new Foo("Hello, World!");
bar.Foos += new Foo("LOL!");
foreach (Foo foo in bar.FooList)
Console.WriteLine(foo.Message);
}
[/code]
It works – I wouldn't recommend using it in production code though… Maybe more interresting is what would happen if we modified the CIL for an event to accept a non delegate type. Well let's try it and see what happens!

The original C# code:
[code lang="csharp"]
public class EventTester
{
private List