The tax deadline this year is 4/17/2012, not 4/15/2012
If you file an extension, it is an extension of time to file, not to pay!
If you e-file before the deadline, you still do not have to pay until 4/17/2012 (postmarked)
If you cannot pay by 4/17/2012, pay as much as you can by 4/17/2012.
You can apply for a payment plan HERE
Or you can pay with a credit card: 1-800-2PAYTAX (they charge a service fee.)
Some other alternatives if you can't pay are HERE
4/17/2012 is also the deadline to amend a 2008 tax return for a refund