Have you ever cringed at a student's Power Point presentation that was obviously thrown together at the last moment using images clipped off of random Google image searches? Take a moment when introducing a PPT assignment to introduce students to the concept of copyright when using images - it's just like copying and pasting blocks of text in papers! Here are some sites where students can obtain images that are either in the public domain or licensed under Creative Commons....
Use You Tube videos in your classroom presentations, but without the ads, the comments and the surrounding noise.