Collaboratively create a word cloud to assess the prior knowledge of participants or have participants introduce themselves to the group.
Answergarden.com is a collaborative word cloud generator. It is friendly with ALL DEVICES!
Create an aswergarden by going to the web site and posing questions.
Have participants go to the website and contribute responses. You can use the automatically generated QR code or just give them the web address.
Once folks have contributed you can easily export to tagxedo or wordle to make it pretty!