Did you know that Microsoft gives you over 150,000 images you can use for free in your presentations? Most presenters are unaware of this since when you load the software on your computer it doesn’t load any photos. Microsoft has an online library of photos that you can search from within PowerPoint. In PowerPoint 2010 and earlier, you can search this library from the Insert ClipArt feature by setting the search to only look for photos and including the online collection. In later versions of PowerPoint they allow you to choose to Insert a Picture from the collection more directly. This is the first place you should look for photos.
Find photos in Wikimedia Commons
If you don’t find the photo you are looking for in the Microsoft collection, the next place I suggest you try is the image collection at commons.wikimedia.org. This is the image library associated with the online dictionary Wikipedia. People have uploaded millions of images that you can use in your presentations. Be sure that you follow the guidelines on citing the source of the photo and you only use photos that are allowed to be used in commercial projects without having to make the result publicly shareable. There is no cost to use the photos, but you must follow their rules of usage.
Dave Paradi <firstname.lastname@example.org>