I have recently become a member of a couple of organisations dedicated to causes that I am interested in - Amnesty International, and an environmental group with a very realistic and practical approach to protecting the environment.
I was motivated to do so because of the influence of money in politics. I decided that, if business interests are going to use money to influence political outcomes and marginalise the power of my vote, I had better fight fire with fire and put some of my own money into the mix to fight for what I believe in. I therefore tried to select groups who will use the money to maximum effect whilst still maintaining the ideals I want to support.
Really, this is quite a depressing situation. I feel like I shouldn't have to pay to have my views expressed, but when there are oil companies and anti-abortion religious extremists and weapons manufacturers and drug companies all pouring money into buying political influence it is not going to do much good to refuse to participate on the basis of principle. Recently, however, I've started to belive that it's possible that the only way to beat those who seek to corrupt the political process to serve their own interests is to get down in the mud and fight them with their own tactics and weapons - money, and to a lesser extent media spin and hidden influence of public figures. I think it is possible to do this and still maintain the moral high ground, because the 'interest' I wish to protect and serve is not financial, nor will it benefit me more than anyone else.
It's a dangerous path to take, though. There are so many examples of people who were once idealistic, decided they had to be in the game in order to win it, and ended up caring about the insider dealing and their personal interests more than the ideals they originally sought to champion. They say "anyone who isn't a communist when they're 20 is a coward; anyone who's still a communist when their 40 is an idiot," but to me that is just a lame justification for the tendency people have to lose sight of their higher aims and ideals and focus entirely on their own circumstances. I think that it's the person who is 40 and who has lost all of their idealism who is the coward and the idiot, not the person with the courage to still believe in something better and to fight for it.