Poll Everywhere is an amazing service. You can poll your students via text message (or internet) for FREE, up to 40 participants. The way it works is you create an online account at Poll Everywhere and share a code for your students to text to. The responses are tallied immediately on your online account. You DO NOT get text messages on your phone (wow, that would be a mess!).
Here is a 2 minute video that explains:
Text polling can be used in the classroom as described in the above video. Text polling could be used online by providing the text code (as the video shows) and asking students to provide feedback on a question within the day (or some time frame that you determine). Remember, the feedback you receive will be tallied and summarized as shown in the video on your online account – NOT YOUR CELL PHONE!
I really look forward to incorporating this in my courses!