Not breaking new ground here, just a simple suggestion for increasing student participation. I always have a pack of index cards in my bag that I carry to class. If class participation stalls, I can break out the index cards. Whatever the topic happens to be, I pose a few questions and ask students to write their honest answers on an index card. I tell them not to put their name on their card unless they want to. When students have finished writing their responses, I collect the cards and read some of the responses. I don't identify anyone by name. Usually it only takes 4-5 cards to get to something that sparks discussion. It's common for a student to raise their hand to respond to something I've read on an index card. I love it when students respond to something a peer has said. I'll continue to read responses from the pile, occasionally asking the class "Does anyone want to take credit for this?" Sometimes no hand goes in the air, so we don't know who authored the response, but in many cases a student will take credit and elaborate. This leads to more debate and discussion.
So that's it. Trust me, everyday is not an index card day. Like any other technique, it can go stale if it's overused. It's just another tool in the box that helps keep class discussions going. And keep in mind this is a great way to involve shy students in the discussion. If I read 15-20 cards from the pile, I've most likely included cards written by students who tend to be quiet in class. So this is a way to increase contributions across the board.
If you've never done this, give it a try and let me know how it went. And please share your ideas for stimulating participation.