California case: Nordyke v. King
Good summary of it at CalGuns Foundation. I was surprised to learn the suit is still alive!
In 1999, Alameda County passed an ordinance banning guns on public property, including the location where the gun show was usually held. A challenge was filed in Federal district court, and the judge spontaneously raised the 2nd Amendment question, before ruling against the challenge. To be precise, he denied an injunction at the outset of the case. He didn't dismiss it.
It went to the 9th Circuit, which asked the California Supremes to clarify a state law question.
The 9th ruled in 2003 that plaintiff had no standing, following prior 9th Circuit rulings -- it was a state right and he wasn't a state. But the majority opinion suggests that, but for the prior rulings, the judges would have ruled differently, and one judge concurred to say he thought the prior rulings were dead wrong.
After that, the case went on in District Court (all that had been denied was an injunction at the outset). In 2007, the District Court ruled in favor of the County, and an appeal was filed with the 9th Circuit. After Heller, both sides have requested to brief the 2A issue. Good news is that the same three judge panel will hear it.