The U.S. currently collects about $2 trillion annually in taxes. About $1 trillion of that comes from individual income taxes. Corporations pay about $200 billion, and another $100 billion or so is collected from estate taxes and excise taxes on things such as alcoholic beverages and telephone services. Another $700 billion is collected in payroll taxes that fund Social Security and Medicare programs.
from an interesting article about tax reform:
http://www.bloomberg.com/apps/news?pid=10000087&sid=aM97Z_mhEj10&refer=top_world_news
http://www.cipa-apex.org/toomuch/Weeklies/August92004.html
assets:
http://www.globalcustody.net/no_cookie/custody_assets_domestic/