Vote third party in the local elections when appropriate. The EC precludes a third party president (for now...) but local elections are feasible. It may take a while but eventually a third party will get through.
I have gotten called for jury duty many times at various levels but I have yet to make it to a court room. Here we are supposed to call a number the night before and find out if we are supposed to show up. I really want to sit on a jury. I drank the kool aid about civic duty and privilege and think it would be an adventure. And folks should remember... if they are ever on trial, twelve other people will sit for them. It's only fair to take one's turn in the barrel, so to speak.