I think that you should definitely vote for Nader.
The problem with not voting, is that while you and I understand why you are not voting, the media does not, or at least chooses not to air why. By not voting, whether you intend to or not, the message you are sending is that 'the candidates are all good', not that there is a problem with government. Furthermore, one could even say that by not voting, you are voting for Gore and Bush.
However, the above reasons to vote ae not the main reason to vote for Nader. Voting for Nader will increase public awareness of the crimes of government and corporations.
Ralph Nader has so carefully documented countless cases of governmental wrong-doing, and corporate crime throughout his career, and these statistics and facts that he has researched and investigated are supporting facts and evidence for your beliefs. When many people hear and read these facts and instances, your ideas and actions will seem much more justified to them.