Can Keynote be used for mind mapping

Hi. I suddenly have a need for mind mapping and have been looking at the available apps which seem to either be free with saving disabled or ridiculously expensive for what seems like a pretty basic task.

It got me wondering why Keynote couldn't do something like this. Its a pretty staggering piece of presentation software but I've never seen templates or workarounds to use it in this way.

Does anyone know of anybody who has managed this?