from Dan Struebel:
The Hive Group has combined Obama's 2012 budget proposal with past and future budget data (actuals from 2008-2010, the estimates for 2011, the proposal for 2012, and the projections for 2013) and created a really powerful visualization of all the spending. By agency, bureau, function, subfunction, discretionary vs. mandatory, etc.
Check it out: http://www.hivegroup.com/gallery/2012budget/
(Heads up! May require latest install of java to run.)