Here's a link to most of the major text deals, with details & instructions. Looks like MGMM is an ongoing subscription, and HET requires you to sign up every 4 days.
I'm letting my AT&T prepaid phone run out next month, so I am signing up for all of these before my trip next week to see what comes up (and use up my non-refundable balance).
If you're a downtown person, give the Golden Gate 1906 club your cell #. I had an old text in there to reply and join, and when I did it today they replied w/ a $25 matchplay offer!
Saving money in Vegas is always fun!