Joao Alves, a member of the  Images4Education Diigo group, bookmarked Sprixi, and I clicked through to investigate - what an interesting site!  It looks like it could be a very useful school tool.

Go to Sprixi, and enter a keyword or two for the image you'd like.  Here's a screen shot of my search for "cat" pictures. I chose the one that looks like a child's drawing.

Look at the grey bar under the picture, and the greyed out text under the bar.

The 4 columns let you choose what size you want to use - choose the largest if you're going to print, and one of the smaller ones if it's for the web.  Check the information about the image.  For the picture I'm looking at, I can see that

  • the title is  "my cat"  
  • the photographer is  " admin " 
  • I found the picture "via Sprixi.com." 
  • I can use the picture if I give credit with a link back to the author, because the 
  • Image is licenced under a Creative Commons Attribution licence. 
  • The image's size is 422 x 388 pixels."
Click on the green "USE" tab, and an extended window opens:

Here you'll see the URL of the picture, so that you can link directly to it, a "Download the Image with credit" link so that you can download the picture to your computer, with the right information you'll need to give credit to the photographer included as part of the image, and more information about the Creative Commons license of the picture.

When you click "Download", the image is saved to your computer, with a grey bar across the bottom which gives all the necessary photo credit information.

The automatic inclusion of the photo credit will make it very easy for students to post images correctly. I think that having to read about the credits in the download step will help them become aware of what they're doing, too, using someone's image correctly, and giving credit.

Sprixi's FAQ page  says that Sprixi is different because
"Sprixi is "purpose built" to help you choose and use an image quickly and easily. Sprixi is not about tagging or commenting on images, and it is not about browsing a million photos. Sprixi is about finding an image that is useful to you, now."
Sprixi is somewhat of a social crowd-sourcing site, too.  You can't leave comments or tags, but you can vote on whether or not the site is giving you the images you thought you'd see, or that are useful to you:

"How does Sprixi learn? What do you mean by "usefulness"? 
"Sprixi tries to sort images by usefulness - how useful you find an image for that topic.
Images are sorted automatically just by people using Sprixi. Images you click on, rate, use, download or upload are given a usefulness rating. You can also vote for the usefulness of images by clicking on the yes, maybe and no buttons. Votes from registered users are given a heavier weighting."
(I took the screen shots for this post with Screenpresso, a widget that takes the screen shot, provides some some basic editing tools,  and will send the picture to email or Twitter)