In a recent SmartBrief survey, 40% of educators reported that online applications and games are the most effective way to engage students. This blog post suggests three websites that high-school teachers should try. Persuasive Games includes a variety of games used to teach students about everything from the flu virus to debt. GlogsterEDU offers a variety of resources to beef up presentations with text, images and videos, and Vocabulary.com seeks to improve students' word skills.