The PowerPoint activities I've developed here could be used in two ways. Either a zippy fun thing in the last few minutes of the lesson to test what you've studied in the lesson, or an activity which could lead to discussion of grammar/pron/vocab. The template for these games will allow you to make your own.
One word of warning: in my experience, interactive whiteboards don't always react well with some types of animation in PowerPoint. I would advise using the mouse to click on questions or shapes in PowerPoint rather than the whiteboard pen, unless you are really confident about your whiteboard technology.
Game 1: odd-one-out / multiple-choice quiz
Game 2: who wants to be a millionaire
Game 3: treasure hunt
Game 4: anagrams
Game 5: blockbusters (ABC)
Game 6: top English
Game 7: tornado
Make your own PowerPoint games
If you want to know how to make your own, have a look at these instruction videos