You can snag digital photo frames for cheap from just about anywhere these days. If you're looking to make one that's a bit smarter, DIYer Samuel Clay built a digital photo frame that uses a Raspberry Pi and a motion sensor for up-to-date pictures and energy efficiency.
Clay's build uses a Raspberry Pi, a cheap LCD monitor, a motion sensor and a USB WiFi. From there, it's all about software, and the Pi is set up so it automatically pulls new photos from a Flickr account and displays them when it detects movement in front of the frame.
Head over to Clay's site for the full guide on how to make it yourself.