Have you ever wondered where websites get all of those random pictures of people smiling? What about the pictures of attractive women with headsets that are ready to take your call? Or generic business people shaking hands?
Most of the time when you see these types of images online, they were downloaded from a "stock photography" site. These sites let you buy royalty-free photos so that you can legally use them on your website. So the next time you need a generic picture of something, try browsing a site like shutterstock or iStockphoto.
If you're interested, I have two warnings for you. #1, most stock photography looks really really cheesy and stupid (like the examples I used in this post) so you should be very careful about which images you choose and how you use them. #2, while there are sites that offer free stock photography, you generally have to pay more than you'd think to get quality photos and good selection. You can browse for free of course, but be prepared to shell out some cash if you find something you like.