In many posts I have mentioned online tools which could be interesting as a means of setting students homework, creating online cartoons, recordings etc which can later be looked at and discussed in class. Here is another idea which is in vogue but which takes the whole concept of what happens at home / in class to a different level.
Try flipping your class. Forget those up-front presentations. Record them (powerpoint, video, audio, slide presentation etc) and put them online, on your blog for example. Let the students work through the presentation at home. That frees you up in class for much more interesting work be it practice or student feedback on the work they did at home.
Have yet to put it into practice but love the idea and how it could help make classroom time all the more useful and rich. Follow these two links for a little more on the area: