If you cannot get ANY fuel, and cannot bum a ride from a freind, get public transportation, etc.; then and only then use heating oil. The biggest problem is the stuff does not get nearly as refined as diesel fuel. I know people who have run the stuff on a limited basis. Your car will run on it but you can do damage with extended use. It can contain (among other things) higher sulpher, larger poorly burning long chain byproducts which WILL over time clog injectors, add more particles to your oil thereby increasing wear - all in all not good for your engine. The main point - don't do it to save a buck.
My Mercedes users manual suggests the use of Kerosene/Diesel in a 50/50 Maximum for use where non-winterized fuel may not be available. At higher percentages the lubricity becomes a problem.
An old trick I've heard of, is to add used motor oil to kerosine in a pinch. The problem with this is that motor oil will give similar problems to that of home heating oil. From another web site, I have read that instead of motor oil use automatic transmission fluid. The claim is that this burns ashless - important if you want to keep things from fouling. Unfortunately I do not know what ratio will give the best benfit.
I hope this problem does not become an epidemic! All I run are diesel vehicles now - a '96 6.5l suburban, and an '84 300SD.