If you can't volunteer at a shelter due to its physical and emotional challenges, can't write a blog on animal welfare because the creative juices simply are not flowing, can't always donate because it cost money, then there's still an opportunity to make a difference in animal welfare.
You can transport animals to their freedom. Obviously, you must be a licensed driver and have access to a vehicle. The time and place of your participation will be up to you, and also up to devoted and heroic individuals running Yahoo Groups dedicated to transporting animals for free. The Yahoo Group provides the information, and you try to fit in. Remember, sometimes, the difference between life and death is a ride.
Here are two groups I joined recently:
You can see from the map that the area covered by these groups run thousands of miles. Interstate 80 crosses the country from coast to coast while Interstate 95 goes from Florida to Maine. These interstate highways, coincidentally cross each other in my area. If you intend to volunteer, you need not worry about doing the whole trip. You just have to do a leg which seems to be approximately 50-60 miles or roughly an hour and change. The job entails meeting with a driver at a predetermined place, relaying the animals and their paperwork to you, and off you go to meet the other driver at another meeting place. You're part of a chain, really. No one is forced to participate. It's all volunteer work. I am quite eager to do my first trip.