Ready.gov spoof
I think when it's been over three years since I posted a funny link, I get to post it again. So, click here (or, similarly, here) for a different and hilarious take on the Ready.gov signs. Examples:

If you are sprayed with an unknown substance, stand and think about it instead of seeing a doctor.

Do not try to catch up on filing and paperwork during a terrorist attack.
If you are sprayed with an unknown substance, stand and think about it instead of seeing a doctor.
Do not try to catch up on filing and paperwork during a terrorist attack.