Free as in Beer?
Stock Photography Sites
Stock photography sites let you search for and purchase /img for use in your presentations (or other media like print, t-shirts, etc.). Some of these sites charge per photo (typically in the form of credits), while others offer a subscription that grants access to their library for as long as the subscription is renewed. If you search, you’ll find a huge number of such sites – I’m only listing sites that I’ve used personally or people I know (other speakers or authors) have recommended to me.
pxhere.com
Licensed with CC0. Literally do whatever you want with the pics.
labs.openai.com (DALL-E)
AI-generated images from prompts. Resulting images are yours do use as you please. You need an invite to access - mine took a few days in summer 2022 to get.
UPDATE January 2024 This is now baked into ChatGPT, making it much more accessible.
iStock (formerly iStockPhoto)
Now part of Getty Images, iStock offers both a credit and a subscription model. A typical image might start at 7 credits, and you purchase credits for somewhere between $1.40 and $2.00, depending on how many you purchase at a time. A subscription is around $200/mo.
shutterstock
The shutterstock site offers both subscription and pay-as-you-go options as well. Their starter pricing is $249/mo for a subscription or $29 for 2 images. In addition to photography, vector graphics, video clips, and icons, they also offer music.
fotolia
Fotolia includes images, vectors, and videos, as well as logos. Purchase credits for between $0.74 and $1.40 depending on how many you buy, or subscribe for as little as $25/mo. Special 1-month trial from this landing page.
Free Images
These sites will let you find and use images free of charge. Most of them require some form of attribution, and many are only licensed for use non-commercially.
Flickr
IM Free
As nice as Flickr is, there’s just a lot of stuff there. IM Free offers curated collections of free resources from Flickr and other resources, all ready for commercial use. Examples of collection topics include people, business, icons, technology, food & drinks, and nature.
GetRefe Tumblr
Refe is a marketplace of mobile photos. They have a tumblr with free photos you can use, tagged for searchability.
Gratisography
Gratisography offers a bunch of completely free and somewhat off-the-wall photos for use in your personal or commercial projects.
The Amazing Pattern Library
The Pattern Library is a compilation of patterns that you can use freely in your designs. Consider some of these for your next slide template background.
Free Images
Now owned by Getty Images, freeimages is an older site that offers many free photos, with varying usage limitations.
Death to the Stock Photo (via email)
This site, DeathToTheStockPhoto.com, is run by some fellow Ohioans and offers free stock photos sent to you via email each month, as well as a $10/month subscription to get access to everything they have.
New Old Stock
Little Visuals (via email)
The Little Visuals site will send you 7 /img every 7 days, for you to use however you want. You can start your own personal library of stock photos using sites like this one (and DTTSP above). A good place to keep such things is Copy, which I’ve blogged about previously and which you can get an extra 5GB of storage from if you follow my link.
Creative Commons Search
You can also use search.creativecommons.org to search numerous sources for material that you can use commercially or modify/adapt/build upon. It isn’t a search engine – it doesn’t index or aggregate the results – but it does provide a convenient interface for searching other sites. Currently it works with Flickr, Europeana, Fotopedia, Google Images, Open Clip Art Library, Wikimedia Commons (which I’ve used quite a bit), Pixabay, as well as Video and Music sources.
Thanks to Chris Reynolds for many of these resources!
Update: Just remembered this link to more free image sources.