Richard Byrne recently posted about an update to Socrative.com. I was excited to hear that Socrative is now offering the opportunity to upload pictures to their clicker system. This impacts the teachers I work with greatly because primary elementary students often need an image for a question instead of full text.
I would recommend checking out his blogpost since I am really just piggybacking off of what he has done. I have posted about Socrative in the past, but this should give a fresh update as to the capabilities it possesses.
via Free Technology for Teachers: Check Out The Great New Features in Socrative.