Poll Everywhere could serve as a quick, easy to way both engage students and perhaps make them be held accountable? And then act as a springboard for discussions as to what made an answer right or wrong?
Blogger has helped me get ideas from colleagues as to what does and doesn't work. I think in the future it might be something good for the students to be able to get immediate feedback from one another. It would be a good, go-to spot so that people don't have to go to multiple sites to do things.....one-stop-shopping??