If you don't already know about 81 words, check it out.
It's a site that posts only complete stories of exactly 81 words, and they're kind of addicting. I've been writing one as a warmup for whatever story I'm working on that day.
That word, stenciled on the two guards’ backs made her laugh. She had been in the museum since it had closed, and they had never gotten close to seeing her.
Getting past the alarm wasn’t as easy, but once she had deactivated the sensor on the case, and the pressure plate below the painting, it was hers. Popping it from the frame and tucking it in her bag, she replaces it with her own painting: a bright yellow smiley face.