Vegetable oil can be used for fuel in two basic forms: (1) biodiesel
and (2) what is often known as straight vegetable oil (SVO). 
Biodiesel is derived through a chemical reaction that begins with
straight vegetable oil.  Straight vegetable oil is often derived as
waste from restaurants (waste vegetable oil WVO) or other sources. 
The question is what information is available on the web about the use
of straight vegetable oil as a home heating fuel.  There is
information about using biodiesel.  I have had a hard time digging up
information about the use of straight vegetable oil for home heating. 
The kind of information that would be useful would be about the kinds
of oil heaters that work or don't work; any supplementary equipment
that is needed to make the straight vegetable oil work properly in the
system (e.g. pre-heaters); any information about the sources of oil
that are better for the process, etc.; any information about
recommended blending; arguments why biodiesel is superior, etc. 
Thanks.  The information would be useful to me in the series of links
categorized by the problem or issue they are responsive to.  Short
summaries after each link would also facilitate the research.  If
there are no results, then some kind of explanation of how thorough
the research was to give me confidence that nothing is out there on
the web on the topic.

Don't know if this will help or not, but SVO can be used in diesel
engines and is used a lot in diesel generators to generate
electricity. It just has to be pre-heated first. I sell a book on how
to generate your own electricity that has a lot of info on biodiesel.
The book also has some info on methane that can be used to heat a
home. And... of course solar home heating. You can get a free
biodiesel book at www.electricitybook.com. Here are the resources I
have listed in my book on biodiesel...

http://journeytoforever.org/biodiesel_make.html
http://www.kelseyville.com/biodsl/
http://www.biodieselnow.com/
www.biodiesel.org
www.biodiesel.com
www.veggievan.org

Bill

Since I don't know how to submit an answer, I settle for a comment.
This is what I am going to do and have done. I have tried an oil
burner/heater with using 100% biodiesel, and the problem is lighting
it with electronic ignition spark. Biodiesel doesn't atomize like
diesel does b/c of the viscosity. So I have read B20 should work fine,
but haven't confirmed. What does work is lighting the spray with a
torch by hand, once the combustion chamber of the oil furnace is hot,
it will lite, and continues to stay hot, and it will relite if the
chamber stays hot.

The same goes with WVO, its just thicker than biodiesel. So to say if
you where using a regular oil burner, the oil would need to be
preheated, and added air compression would needed to be added to the
mix before the nozzle, so to get a good atomization to it out of the
nozzle. These guys at waste oil heat have a great system going, but
the burner costs aprox $2600USD, but they claim it works with WVO, and
any other thick viscous fuels. You have to look for burners that will
burn used car oil. Same theory applies to that type of fuel.

http://wasteoilheat.com/inov8/waste-oil-burners.shtml

I plan on buying one here before winter, and installing it in a
bioler, and using an air handler (raditor or heat exchanger) put into
the existing furnace fan system to heat the home. I have pretty good
confidence the burner works, b/c   it uses a compressor, and preheats
the fuel before the nozzle.

In short if you got the money get the INOV8 Burner, and find a boiler
to put it in. Otherwise you can use a babington burner setup for
viscous fluid atomization. But you will have to make your own system
there.

Have fun chewing on that,
Brandon

ah one more thing, my Web site -> BioDieselUser.com

Brandon