If you have the time, inclination and internet connection you can listen to all three Astros minor league games today. MiLB.com provides free audio of many minor league games.
Lexington plays at 9:05 am Central Time. Brad Dydalewicz takes his 0.00 ERA in 17 innings pitch to the mound. (Video of this game is also available for a FEE). EDIT: The Legends gave Henry Villar a spot start instead of Dydalewicz
Lancaster plays at 1:00 pm Central Time. Shane Wolf is scheduled to start. (NOTE: have had difficulty listening to Lancaster through FIREFOX, but their play-by-play announcer assures me that the stream works fine through Internet Explorer)
Corpus Christi gets started at 6:30 pm Central Time. Brian Moehler makes a rehab start for the Hooks.