In the everyday world on "Main Street", U.S.A. you just don't see folks walking around with a long-gun straped over their shoulder- with the exceptions of the parking lots of gun stores, or gun shows, or at a turkey shoot event. Thus it poses a challenge to engage in what is obstensibly "legal" behavior, but the practice is so extremely RARE and outside of the norm of everyday experience that it likely will result in somebody being alarmed even if the behavior is not calculated to cause alarm. Any charge will likely be dismissed, but the court record will still be there.
On the other hand a low-profile presentation of a holstered handgun on "Main Street" especially in Texas , would largely go unobserved , and in the absence of any suspicious, deviant behavior the presumption would likely be that the bearer was some level of LE. I suspect that I could enter most retail locations in Texas with my an uncovered IWB holstered Glock, and never raise an eyebrow - just as I do in Colorado Springs. On the other hand, I wouldn't get 10 feet away from vehicle with a shot gun before 911 would be ringing off the hook in Texas, or Colorado Springs.
Go figure. One is currently perfectly legal but will likely cause alarm. The other generally isn't legal but is less likely to cause alarm, and therefore would draw little or no attention.
Hopefully the 2013 legislative session will fast-track repeal of the 46.035(a) public display proscription, and at least allow for licensed OC. A long gun carry movement shouldn't be necessary, except as a last resort. I think most folks would find the practice awkward and very limiting outside of some sort of orchestrated demonstration event.