A few others that are similar:

- fibonacci sequence to n (ooh, look, isn't recursion pretty) - parallel map (simple demonstration of parallelism in languages that allow it)

[slightly more involved, webapp hello worlds] - basic blog (various MVC web frameworks, normally along lines of if I run commands x, y and z I get models, views and controllers and it all works) - basic todo application (various frontend frameworks) - basic chat application (as a realtime demonstration, generally for websockets)