If you're planning to join either TechNet or MSDN @ our Technical Roadshow in Birmingham this week (Tuesday is Infrastructure day, Wednesday is Developer day) then I recommend considering the Train as your means of transport if you're travelling from London.
I'm not a "Green Freak" though I have ordered a Hybrid car to replace my Saab Turbo as it's fun to drive (believe it or not!), is high-tech and has less than 50% the CO2 emmisions of my current car (Saab 93 Aero).
The train makes sense for my journey as Birmingham Internation Station is less than a mile away from the Venue - the National Motorcycle Museum.
The map shown below was taken from streetmap which I find to be a very useful resource:
As you can see I've subtly annotated the map with a nice(!) green pen to show where the station and venue are located.