Phota - as Bryan points out, very likely the DJ will do a pretty good at this since that's his task.
He knows his job, what's current, what works, and will be able to size up the crowd and it's mood pretty fast. I wouldn't be too concerned with coming up with suggestions for him - things will happen on their own and it's just a matter for you to be alert to those opportunities and capture them.
Can anyone suggest to me titles of songs that make for goofy dancing antics (and even better photos) during the reception?




