You can use ESPN Radio, but that may just be MLB radio through another service. Whatever it is, it works. I listened to the Astros-Royals game yesterday (wish I hadn't - it was depressing! ) on UA5 from LHR to IAH. I kept refreshing the Twitter feed off the team site, and the Tweets were definitely ahead of the radio feed by a minute or so, it seemed. However, the signal didn't come in until we were over the US, around Maine or thereabouts.