Javelina are fun to hunt. I've done it a couple of times at Chaparral WMA in south Texas before. My kids got drawn for the youth hunt in February. You might check the TPWD website and look at the draw Javelina hunts coming up early next year, and inquire close to the hunt dates if they have standby spots.
Chaparral never turns away (or at least hasn't in the past) standby hunters for the Javi hunts. I know that there are other WMAs conducting Javi hunts in the same time frame.