UCD has licensed 2 “virtual” clicker sets that can each accommodate up to 500 students.
These clickers work in the same manner as the hand held devices but now the student uses their mobile device (laptop, tablet, phone etc.).
You can install the control software directly onto your laptop (it integrates with Microsoft PowerPoint) and the students can use their browser to access the quizzes or they can download an app for their tablet or smartphone.
UCD has upgraded its wireless networks over the last year or so and handling large amounts of wireless devices in a classroom is no longer an issue.
There is a full instruction guide, FAQ's and downloadable examples of quizzes in the "Resources" and "Support" sections of the Quizdom website at http://qwizdom.com/support/