The best Earth Day activities are those that keep on helping Mother Earth. They are especially good when they also benefit you - for example those CFL bulbs or Energy Star appliances will cut your power bill and save money over time. Or, get yourself involved in long term activities that help - I've just become part of helping to monitor streams as part of a very extensive program by Friends of the Shenandoah River. We also just planted several evergreens, blackberries, and will add raspberries this weekend.
In addition to events and programs, notable things are happening across the state. VA Tech is converting its diesel fleet to B-10 Biodiesel, a 10% biodiesel/90% regular diesel mix that has been shown to cut emissions. Last year a friend in NOVA converted her VW Beetle to run on used cooking oil or diesel. She gets the oil from several local restaurants (has ads on the car), runs it through a filter in her garage, and gets 90% of her fuel for free. She says the Beetle runs better on used french fry and chicken frying oil than on regular diesel. Would that be corn oil?
Of particular interest here in the central Shenandoah Valley is the possibility of taking something we have tons of - poultry litter - and converting it to something to help wean us off foreign oil. VA Tech is working on a mobile processor that superheats the litter and converts it to oil for heating (poultry houses use lots of heat in the winter), fertilizer, and noncombustible gasses. There are some bugs to work out, but it is innovation like this - which has practical uses and economic viability - that will help provide solutions to our environmental and energy problems. More about the litter in the Washington Post.