Derek Bruff is a Maths academic who has written both a book and blog pages about using voting systems in teaching. The book “Teaching with Classroom Response Systems” sets out a taxonomy of uses. You can see a presenation I helped put together about this at http://prezi.com/oqxkdtndyqrw/bruffs-taxonomy-of-voting-questions-and-question-design/
The blog pages include posts with examples categorised by use (eg team-based Learning or peer assessment) and question type (eg conceptual or case study questions). Both are well worth a look if you are want more ideas on how and why you might use voting systems.THe blog also considers Backchannels (text, Twitter etc) and visual learning.