Impressive. If only I knew what the hell he was talking about. This is one of those instances where a "foo" example isn't appropriate and should be replaced with one based on real life.

I only disagree that collections are code smell. Generics are simplifying signature of collection but not Composite Pattern. Composite Design Pattern helps to build tree structure collection. For example whenever you need to manipulate with nested objects such as Family Tree, XmlNodes, WebControls, etc Composite Design Pattern is the best approach for it.

“The Rule of Thumb:
Usage of composite pattern is usually appropriate whenever there are hierarchical tree structures where all the tree nods are of the same type. “
Design patterns in real world use case scenarios, posted by Nikola Malovic - http://blog.vuscode.com/malovicn/archive/2007/08/16/design-patterns-in-real-world-use-case-scenarios-composite-part-2.aspx

Message for yesthatmcgurk, try to look at the Nikola Malovic blog post I mentioned above. Composite pattern is very simple, useful and unique.

Point taken with the FooBar, next time there will be no FooBar ;-)

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Why should the Composite pattern only deal with Tree structures? (The Composite Design pattern allows a client object to treat both single components and collections of components identically)

And anyways the composite class could easyly be rewirtten, to accept 2 instances of IFooBar. Then we could greate a tree structure by creating multiple coposites.
But whats the point? the list composite solved the problem?