Timely information from usa.gov:
“You’ve got six days left to submit your 2011 federal tax return. April 17 is this year’s deadline.
Here are some last-minute resources:
• Tax Forms and Publications
• Publication 17 — The Only Tax Guide Most Individuals Need (PDF)
• Tax Benefits — You May Qualify
• E-file Your Taxes
Within 72 hours of e-filing or 4 weeks of mailing a paper return, you can check your refund status.
If you cannot file your tax return by the deadline, then request an extension. Keep in mind that an extension does not give you additional time to pay if you owe taxes. You’ll need to estimate the amount you owe and submit a payment in order to avoid interest and penalty charges.”