to reach your students in classroom you can use some already made and wonderful social networking applications for the mobile phones, these are the application that's already running and they all have it in their mobile phones now.
so the question is now, How can you use social networking in your teaching process.
for example :-
* in case of projects deadlines you can make an event on facebook to remind students with it. (in this case no execuse will be made as every and each one go to facebook more than once a day)
* you can upload video for you explaining hard parts or hard problems on youtube (no need for you to appear on the video, you can display just the powerpoint slides or the white board while explaining). and also you can get feed back from students comment.
* you can post a challenge or a question every week on your facebook wall and let the students comment with their answers so you can review it later.
* also you can post grades on your wall so student can check them once they are uploaded
all these are ways to use the social networking to enhance the learning process.
if you like my suggestions please tell me and I will write more.
also you can check this if you want a detailed idea about the use of social networking in learning process
http://bloxx.com/downloads/resources/bloxx_whitepaper_SMedu%5BLR%5D.pdf
by
Naveed sajid , Assistant Professor , Cholistan University of Veterinary & Animal Sciences, Bahawalpur
use of mobile should be prohibted in the class but is good for comunication b/w teacher and students for guidence, test date alarming, notification of assingments and so on.