I have been to the Alamo. Alamo Lodge No. 44 actually opens Lodge in the Alamo. I think it is a moving experience to attend Lodge in same location as the Alamo heroes. There are not many Worshipful Masters that can say they have opened Lodge in the Alamo!
December 12th with the new GM presiding over the lodge, the introductions take for ever but it's really good. Also, bring your own apron, they normally don't supply them. I will be there for sure if someone wants to meet let me know and we can meet in one location. To the original question the experience is very moving as not many masons can say they sat in lodge in the Alamo, and it's good to see brothers drive in from surrounding area, it's also a true Texas Masonic experience.
I would like to attend as well. Do you have to be invited or register for it or can you just show up?
Just be a Master Mason in Good Standing, it's easier if you know someone who can vouch for you. They should be sending out something soon for an announcement, I couldn't find anything on Alamo Lodge's website or the GLoTX website. Let me know if you want to meet up.