I would also often see signs that began with "Texas sized....." For example, "Texas sized savings!", "Texas sized dinner!", "Texas sized deals!", etc. etc.
I don't buy the 'original' mambo-jambo. Just a way for the locals to get off on feeling superior. On the occasions I go to the North End when somebody mentions they are to the effect of "original" I always feel like "hey I don't tell you MY problems".
When I first looked at the thread title, I thought you are talking about signs of intelligence. But then I saw you are talking about Texas....
Now hey there! Dell and Texas Instruments are both based in Texas and of course NASA mission command is in Houston.
Don't forget about AMD, Bell Helicopter, and what used to be Consolidated Aircraft/General Dynamics (home of the B-36 and F-16). Dr. Pepper is also a Texas invention.