As of this moment the estimated unpaid salaries is $1.59 TRILLION and estimated food vouchers unpaid is $110 BILLION.
Dan Delany took a simple look at furloughed employees due to the government shutdown. There are tickers for duration, estimated unpaid salary, and estimated food vouchers unpaid, but the main view is the interactive tree map that shows furloughed proportions by department.
Data was nicely collated into one spreadsheet from a bunch of government-released PDF files (of course), and the code for the page is available on Github. [Thanks, Dan]