This strange barcode is a QR Code, which is found on websites and printed materials. When scanned with your mobile phone, it can quickly link your phone to websites, open videos, create text messages, transfer electronic business cards (i.e. vCard), etc. It saves time and risk of error from having to type in the information directly. You simply open your "barcode scanner" application and scan the barcode. It will request to perform an action, in this case to send a text message.
Here are some sample QR Code readers for smartphones:
This barcode is used to subscribe your mobile phone to text alerts from Dubuque AYSO's Twitter account (such as game cancellations and other updates).
It automatically sets up your phone to SMS text follow DubuqueAYSO to 40404.
The barcode below is used for "leaving" Dubuque AYSO Twitter SMS text messages, stopping all incoming texts from Dubuque AYSO.
It automatically sets up your phone to SMS text leave DubuqueAYSO to 40404.