We are bombarded with images all day from every direction. Especially through our devices: phones, tablets, and computers. The students rarely tear themselves away, (except in my class, when I will confiscate the phones if they are not actually part of the lesson- but that's a classroom management issue that we don't have to get into here).
Many teachers try to take advantage of this electronic compulsion, to harness the power of this addiction for good instead of evil. Sure, phones and laptops can be great research tools, and as long as the students are engaged in the project that they are researching, it can work.
To support this initiative, teachers of all disciplines must build lists of good sites for students to visit. For artwork, there are plenty, the trick is to find ones with classroom-appropirate content. Many online sites are great but veer away from PG content too easily. So teachers have to preview the sites regularly. Here are a few for art classes that are amazing for research and inspiration:
This next one has the best currently-created work from creatives around the world, but unfortunately is only suitable for senior level classes as the content can easily become questionable. Definitely one for teacher preview, however, worth the effort for the wonderful variety of artwork:
A few more with a similar situation: