When writing a post without a specific screenshot, a blogger (such as myself) needs to come up with an appropriate image. That image must be licensed for use -- you can't just take any old image.
What I usually do is go to Flickr and search for Creative Commons licensed images, with a "commercial okay" provision. I then upload the image and tag it manually, because you still have to provide proper attribution and link up to the creator's page.
That's why I was so happy to find ImageCodr. This tool basically takes all the hassle out of this process and provides a solution that is just about perfect.
I used ImageCodr to link the image at the top of this post. If you examine it in some detail, you'll see all of the small details were taken care of. There's a clear CC logo (with the exact licensing terms for this specific image) and the name of the photographer with a link to their Flickr page. The image itself is linked to the image page, and correct alt text is used (which you can see if you hover over the image). Also, the CC logo links to the CreativeCommons.org website and the license explanation page. This is definitely more information than I could have packed into the image, and it took me exactly one click to get it done.
ImageCodr provides a quick Flickr search for CC-licensed images (which you can also do on Flickr itself and by using a Saved Search in Firefox), but it also provides a nice little bookmarklet that you can drag onto your browser toolbar. You just click it when you see an image that you want to use.
If only they fixed the code so that it middle-aligns properly, this could be a service that I would use on a regular basis. Still, it's a very handy tool.