I am looking for some ideas around creating a series of user friendly charts where for ony one specific metric the user can select from up to 10 business units, which ones to compare on a single chart.

A chart with all 10 lines would be too busy but if a user wanted to look at his/her BU and maybe 2 or 3 others which are close in size then the chart would be useful.

I am imagining a box where the user can choose a few BU's and graph just those. If the user wanted to change his/her selection they could by unclicking/clicking on the choices and a new graph would be generated.

Any thoughts?