I was having surgery on my ankle in 2005, getting a few pins placed because I'm super graceful and broke it. I woke up to hearing what sounded like a drill, and feeling a lot of pressure at my foot. I didn't feel any pain, thank goodness.
I opened my eyes and looked directly at the anesthesiologist, who immediately said "hold on. She's waking up." Everyone kind of stopped what they were doing, and then I went back under.
When I came to again, I was in the recovery ICU with the doctor. I asked her how long into the surgery I woke up, and she told me I was only out 15 minutes before I needed more anesthesia. She also told me I'd scared the s**t out of her, because it was the first time anyone had ever woken up on the table in her experience. Granted, she was fairly young so I don't think it's all that uncommon.
She was really cool about everything though. She asked if I'd been afraid and needed someone to talk to, and I told her no. I was never scared or in pain, so as far as I was concerned it was just a weird experience during my otherwise successful surgery.