For the love of all that is holy, get out and vote!
I know it's easy to say that one vote doesn't make a difference, and there is some truth to that statement. However, you can't have a crowd without the individual people, and you can't get the large numbers of votes without the single ballots.
Yes, voting matters. Yes, it makes a difference. Please, please, please go out there and cast your ballot.
On a related note, I called my parents as I was walking out of the polling location after voting. It turns out that they were also just walking out of their polling place as well. Even thought we're separated by three time zones and close to 3,000 miles (4800 kilometers), we ended up voting at exactly the same time. How's that for a strange coincidence?