If you think that you'll be absent on Nov. 3, then you can go to 4367 Headquarters Rd. and vote by filling out an absentee application in the office. So you can do it all while you are there, and it should be pretty painless.
You can do this if you live in the following areas:
2) North Charleston
4) Mt. Pleasant
5) Seabrook Island
You just have to be registered, and bring your ID!