A good piece of advice i heard was to buddy with the person behind and in front of you. Hold their places if they have to go to the bathroom, etc.
Be prepared to wait, dont wear your candidates shirt to the polls (or turn it inside out if you do), have ID on you, bring a book, some water, medicines if you are on them (
!). If you are in line when the polls close, YOU ARE STILL ABLE TO VOTE.
If you get hassled, use your cell phone to take a pic of the person, or use the recording feature to record what they said if possible. BE SURE TO CAST A PROVISIONAL BALLOT IF SOMETHING HAPPENS AND YOU AREN'T ABLE TO VOTE!!! The provisional ballote DOES COUNT if all your information checks out.
Celebrate responsibly, please. We all know there are some unstable people who may become unhinged when Obama is announced the winner.
(Or McCain, for that matter). Just be careful and celebrate in safe environments.