Flickr photos are a very hot commodity. Flickr is a photo sharing community where you can upload your photos and share them with everyone you know. You can also add comments on photos you like or dislike for whatever reason and provide the author comments.
Flickr hardly has any ads so they do not take away from the experience of viewing great photos. However, they do require you to upgrade to a pro account for unlimited uploads and sets. This upgrade also removes any ads you may find but probably is only worth the money for those who are going to be taking a lot of photos.
The great thing about Flickr is that many of the photos carry a creative common license. This is different than “all rights reserved” which traditionally has meant that only the author of the work could use the photo.
With a creative common license you are free to use and in some cases even modify the image on your website. There are several different versions of the website so you will have to check carefully what the particular license the photo you are in has. You will see on Flickr that under “additional information” on the right sidebar of the photo that either has something that says “some rights reserved” that you can click or “all rights reserved” that you cannot click. If the photo says some rights reserved than you will want to click it to get a good look at the license.
The most common license you will see will be called creative commons attribution 3.0 unported. This license allows you to share the work and adapt it to your desires. However, you “must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).”
Basically what it boils down to is if you want to use a photo you find on Flickr, you use the photo and make sure you follow the license. You need to link to the photo and also it is a good idea to link to the author who made the photo. You also need to link to the particular license of the photo. This is an important step and many people forget to do this.
As I mentioned earlier there are many variants of the creative commons license. Some licenses do not allow you to modify the image. Others do not allow you to use the image on any commercial websites. All of the different combinations and types of the creative commons licenses can be found at http://creativecommons.org/licenses/.
Finding photos on flickr and using them on your website is a great way to attract audiences and keep them back. However, I would not try do use these on Associated Content if I were you because I do not think it is currently set up to do so. Instead it is better to find images on Wikimedia commons that are in the public domain.