If your residing in the UK then its likely your council tax bill was frozen this year - Hooray! The consequences are you may suffer council cut backs, as they try to claw the money back - Booo! That's why Drayton tip do not accept waste cooking oil any more....So get in touch with me instead or ask one of the guys at the tip
You can listen to my interview here :-)
Biodiesel does not seem to be regulated very well in the UK. Be careful what you buy and never assume it's good quality fuel. There are two tests to put your mind at rest. The Wanquist test measures the purity: dissolve 3ml of biodiesel into 27ml methanol and shake, leave to stand. Biodiesel is soluble in methanol, any drop out is unconverted vegetable oil. 

The second test is easier: add 50% water and 50% biodiesel. Shake and leave to stand. The bottom water layer should be clear, cloudy water indicates soap contamination.
I have  6-10 minutes of fame on Monday! Tune in for a brief discussion about biofuels on BBC Radio Oxford.
Hyper-miling is the term used for driving frugally. Anticipating the road ahead, minimising brake use and coasting down hills. There's lot's of techniques on the internet from modifying your car to more controversial methods. I managed to get 47mpg on the way to work last week and I'm sure 50mpg is possible. Not bad for a two ton lump.

Bio users change their engine oil at a regular 5-6k miles. For me this means getting the car up the ramps, removing the splash guard etc. I found a website called "quickvalve" and they make sump valves to replace the plug. All you do is turn the tap, drain the oil and refill - perfect! I think you can make something from standard plumping/gas parts. The local hydraulics shop is on the case!
I am working on an e-book on how to make biodiesel. Its taken me several years to get to a stage where everything works perfectly. The main aim is to simplify the process and avoid the confusion on the internet. Will keep you posted!
Breaking News  - I now pay 20p per litre for dry liquid oil, solid and contaminated oil will still be collected free of charge. 
Give me a beep if you spot the Passat on the A34!

Embarrassing - Run out of bio