Lifehacker published a great How To article featuring various ways to “de-SPAM” your life. From calls & texts to email & snailmail- chances are, there’s a solution out there.
Android users have quite a few options to block unwanted texters.
PrivacyStar will cost you a few bucks per months, but if their app doesn’t successfully block the offending texter you can contact them and they’ll take care of the problem for you. (PrivacyStar is also available for BlackBerry.)