I never get unwanted text messages, but I know the problem exists because I once had a demo phone that a carrier lent me that would get multiple text messages a day offering discount mortgages, prescription drugs, or other offers commonly associated with email spam. I never bothered to fix it since it wasn’t my phone, but David Pogue over at the New York Times (NYSE: NYT), which faced the problem personally, took the time to uncover the solution for all the top carriers. And, you may want to take note, because as mobile content becomes a bigger business, so likely will spam. AT&T (NYSE: T) sounds like it has the most comprehensive solution, which addresses the issue by blocking all text messages sent from the Internet since typically spam is sent this way. Using this technique, it also still allows you to receive text messages from friends who sent them via their phone. The other carriers have different approaches, so if you have a problem, read about them here.