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.
The schedule:
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.