When I got shingles the first time, it happened on the left side of my head behind my ear running down my neck. I thought at first it was poison oak or something like that, but a nurse friend immediately chased me to the doctor, who diagnosed the shingles and put me on anti-viral medication (one of the -cyclovirs, don't remember which), and prednisone as an anti-inflammatory. The doctor said we caught it early, and it cleared up after being itchy for about two weeks. Shortly thereafter, I got the shingles shot; had to pay myself since I wasn't 60 yet, and my insurance at the time only paid over 60. Oh well. Best 200 bucks I ever spent.
About two or three years later, I felt some itching behind my right ear. Checked in the mirror, and wouldn't you know it, looked exactly like the last time, except on the opposite side of the head. Called my physicians center that night, my doctor happened to be the on-call doctor, and didn't even have me come in, just faxed the same prescription as last time to my pharmacy. I was on drugs by next morning, and it never progressed beyond the mild itch and cleared up after a few days. No big deal at all; the doctor gave all credit to the shot.
So get the shot. Especially if you've had shingles, definitely get the shot.