Showing more than one engine line on the analysis board?

Currently on the analysis board the engine always shows the best move. Sometimes I would like to know what the engines 2nd and 3rd choices would be. It would be cool if we could add an option for this. Since the engine is calculating these lines anyway it shouldn't require more computer power just to show them.

I believe that would help players analyze and understand games.

The SF team claims that if you want to see evaluations with secondary variations then there is some speed reduction:
http://support.stockfishchess.org/discussions/questions/1327-alternative-moves

The main problem is building an effective UI for it.