The IRS is a kinder and more warm and fuzzy IRS than it used to be years ago. Having said that, if they don't get their money they will hunt you down. Like any problem, the best way to deal with it is head on. Call them. Tell them your situation. They actually do want to help you as long as you are straight with them. They will set up a payment plan. If you simply can't pay anything at this time, they might defer until a later date. If you ignore the problem, it will only get bigger and much more expensive, and then they won't be so warm and fuzzy.
Best of luck,