I'll just re-iterate the obvious; It took one Simon and Shuster's grammar volumes to help solve this mystery. Don't use a semi-colon like a comma dammit! You don't say, "John and Sue are on vacation. They brought their swimsuits; beachball; and their beach towels." It's not proper grammer. The correct way would be to say, "John and Sue are on vacation; they brought their swimsuits, beachball and their beach towels." They're supposed to be placed at the end of complete sentences; especially if you have more to say about the particular subject. Cool huh? Now run and tell all of your friends about it.