September 24 note: I've fixed the link so you can click over to Karen's weekly art invitational now.
Daily artist Karin Jurik is hosting a most amazing blog! Once a week she posts a photograph and the painting she's done from that photo, and she invites readers to do their own art from her photo and send it in. She posts all that she receives. The first photo was of her dog Jake. The second was a beach scene. This week's photo, the third, is of a man sitting on a park bench reading a newspaper.
The blog is more than an invitation. It's also an art lesson. You can see how different artists have cropped the photo to emphasize one part more than the rest. You can see the different color choices people make. You can see where they've added highlights or have chosen not to. Scrolling through the creations can take a few minutes (the first week she had 54 people take part), but it's worth it. Spend some time with Different Strokes from Different Folks.