Whilst i dont actually make my own biodiesel i do have some potentially useful info for you regarding disposal of glycerine. Australian Biodiesel Industries in Rutherford(30min West of Newcastle), aparently, sell their glycerine byproduct to the power station industry in very large quantities. Believe it or not, the power stations spray their coal with this stuff prior to burning it, so im led to believe, to improve its combustion.
Now ive not looked deeply into it, as i would have thought the coal burned quite nicely on its own however, the above is relayed to me directly from a lab technician at the Rutherford plant. You probably don't have a powerstation laying around in your backyard dying for a little nitro boost , nor is a large commercial station likely to purchase a couple of jerrycans of glycerine off you but....they might take it for free???(failing that, there are plenty of coal trains travelling in and out of newcastle you could dump some onto ).