We also live in a 'safe seat' so there is a feeling that my vote wont make a difference - but if you have a candidate that you do support they might value your vote even if they don't have a chance of being elected. We have heard alot about MPs expenses etc but there are still candidates who put themselves forward for the 'right' reasons and would be encouraged to know that there are others who share their views and (in some cases) passion for what they believe in.
This was my point. I'm not telling people to vote. If the reason is they can't be bothered getting off their butt to go to the polling station then fine but if it because they want to make a point, well not voting won't get that point made. At least vote Green as they do so much for such little reward and are not bent. Of course if you don't care about the environment then don't vote Green!