What's Affected by a Government Shutdown?

http://www.usa.gov/shutdown.shtml

Below, find an overview of some of the government services and
operations that will be impacted until Congress passes a budget to
fund them again. For 
detailed information about specific activities at Federal agencies,
please see federal government contingency plans.

Vital services that ensure seniors and young children have access to
healthy food and meals may not have sufficient Federal funds to serve
all beneficiaries in an extended lapse.
Call centers, hotlines and regional offices that help veterans
understand their benefits will close to the public.
And, veterans' compensation, pension, education and other benefits
could be cut off in the case of an extended shutdown.
Every one of America's national parks and monuments, from Yosemite to
the Smithsonian to the Statue of Liberty, will be immediately closed.
New applications for small business loans and loan guarantees will be
immediately halted.
Research into life-threatening diseases and other areas will stop and
new patients won't be accepted into clinical trials at the National
Institutes of Health.
Work to protect consumers, ranging from child product safety to
financial security to the safety of hazardous waste facilities, will
cease. The EPA will halt non-essential inspections of chemical
facilities and drinking water systems.
Permits and reviews for planned energy and transportations projects
will stop, preventing companies from working on these projects.
Loans to rural communities will be halted.
Hundreds of thousands of Federal employees including many charged with
protecting us from terrorist threats, defending our borders,
inspecting our food, and keeping our skies safe will work without pay
until the shutdown ends.
Hundreds of thousands of additional Federal workers will be
immediately and indefinitely furloughed without pay.

The following services that will continue during the government shut down:

Social Security beneficiaries will continue receiving checks.
The U.S. Postal Service will keep delivering mail.
Active military will continue serving.
Air traffic controllers, prison guards and border patrol agents will
remain on the job.
NASA Mission Control will continue supporting astronauts serving on
the Space Station.