The deadline to file your return is April 17, 2006. For 2006 tax year by filing a "FORM 4868, APPLICATION FOR AUTOMATIC EXTENSION OF TIME TO FILE INDIVIDUAL INCOME TAX RETURN", the IRS will grant the taxpayer a six month extension to file his/her tax returns.
Your deadline to file a tax return is now October 16, 2006. Please be aware, an extension of time to file is not an extension of time to pay."
Here is the link to the IRS site to download this form along with the instructions.
About.com: http://www.irs.gov/pub/irs-pdf/f4868.pdf