Using Cellphones in the Classroom (Constructively)

While some scholars may question the value of introducing leisure-associated technologies into the classroom, education blogger Steve Dembo offers a short list of ways cellphones can be used to enhance the learning process:
1) Check the spelling/definition of a word
2) Research a topic
3) Look up reference images
4) Pull up maps (even with satellite imagery)
5) Document a science lab with built in digital camera/video
6) Fact check on the fly
7) Mail questions to the teacher that they might be embarrassed to ask
8) Classroom response system
9) Take quizzes
10) Record and/or listen to podcasts
What are some other ways of constructively integrating cellphones into the classroom?—Catherine Rampell