Many Eyes

The many eyes project is not focused on security visualization, but nevertheless, it's an interesting and very well done portal. What I really like is the interactivity. Play with some of the treemaps. You can reconfigure them on the fly. Very nice. I also like the explanation of the different chart types and when they are best used.

Swivel / Many Eyes

I found a nice blog entry describing Many Eyes and comparing it to Swivel also. Another project which is sort of in the same vein of these other two, is Data360. It lets you manage time-series data only, but with some nice features ready to help you on that.