If you didn't have a chance to early vote, tomorrow's the day! I tried on Friday, but after an hour in a huge line that moved maybe five feet, I had to leave. I will do my duty on Tuesday.
Revealing Politics has some tips on what to do if you see anything untoward going on. There has been a lot of voter fraud and intimidation going on, so make sure you are vigilant.
They recommend taking photos, although not inside the polling location, upload those to YouTube or email them to firstname.lastname@example.org and see truethevote.org.
Use the hashtag #WatchTheVote
If you want to get through quickly, make sure you know who and what you want to vote for, and bring a cheat sheet, water, snacks and something to occupy you while waiting. I have a feeling that lines will be smaller on Tuesday, since there will be more polling places available.
Good luck Mitt!