Very interesting application of heatmaps. From Sun's excellent FishWorks team.

I second the kudos to FishWorks.

The storage analytics package where this comes from (humbly called "Storage Analytics") is by far the most sophisticated storage performance monitoring and analysis package in existence.

Moreover, the FishWorks guys are just plain awesome: http://www.youtube.com/watch?v=tDacjrSCeq4