Classroom management: Computer Lab

Classroom management is not something easy to do, but what about the classroom management in the computer lab?
I think that there are many ways to have good experiences in the computer lab with the students. In order to get their attention, we can tell them that at the end of the class there is something to hand in, or you can explain them what to do before you go to the lab or just do modelling of the activity. I remember that in my high school the teacher had a program which could take control of all the computers in the classroom so he was able to model the activity. The teacher was also able to see what we were doing on our computers. It is important to have control and to be aware of what your students are doing in your class (even in the regular classes).
It is also important to have precise rules that you state before going to the computer lab and you can also assign to the students places in order to avoid "chaos". It is important to have some kind of routine when you go in the lab so the students will get used to what you do and how you what them to act. But once you have all your rules and that the students are working what can you do to make sure that the students are doing the appropriate work?
I think that walking around the classroom is probably the best technique to make sure that the students are working and doing school work. It is important to be conscious that the students might not do the work, so you have to make sure they are doing it and walking around the classroom is a good way to do this. However, you may catch some students playing games or checking sites that contain pornography. This is something that is can happened and I think that the teachers should be preparing to that. As teachers, we can give a warning or give them extra work, when we catch a student playing games. However, when they are going on pornography website, I think that we have to inform the parents; even though it is only the first time that they do that. You also have to talk with the student. If it is not the first time, you can give the students consequence, extra work, or turn off the computer, basically there must be sanctions because the students know they are not allowed to go on that type of websites.
In conclusion, going to the computer lab with the students can be very stressful for the teacher and I think that we should all be prepare to any eventualities that can happened in the lab during the activity. Do not be afraid to go to the lab with your students because you are not so comfortable with the computers. If sometime happens you can ask the students, who are probably very familiar with the computers, to help you to solve the problem. It is useful to have students who know more than you do because you can ask them to help their friends, while you are helping the others with their work. Going to the computer lab should be a good experience for everyone if you have clear rules and an activity to hand in at the end of the period.