I have had good success with something I read about on a Leerburg article, so far anyway. My dog knows the recall word, but with some distractions would tend to ignore it.
At a dog park if we are in there alone, and my dog saw another dog and owner coming in, he'd run up to that fence. It was a perfect place to proof the recall because there is wide open space and a fence just in case.
He was wearing a prong collar at the time, and I gave a clear recall command (I use "aqui") but he kept running for the fence. So I walked up to him, put his leash on, and gave strong corrections back to the place I called him from, while repeating the word "aqui" as I gave the correction.
Immediately after that, he understandably did not want to venture away from me. But you can train around this by giving a "stay" command then walking away. He can then see that he doesn't have to be right next to you, but he is very likely to stop what he's doing and come when you give your recall word.
I have also heard of people using an e-collar to proof a recall with great and quick success. I do not know the details of how that is done, but if I was in an area with no fences I would definitely go the e-collar route.