eStarling just released a picture frame with built-in WiFi that can receive photographs from any RSS feed or POP e-mail account. You configure the device once using a USB connection and it will automatically update itself over a 802.11b wireless network (even with WEP encryption). Pictures formatted in JPEG or bitmap format are displayed on a 5.6″ LCD.
You could subscribe to a specific tag on Flickr or send e-mails from your cell phone to a special e-mail address such as a free Gmail account. I would love to give one of these to my mom and have it automatically update with pictures from family members around the world.
The picture frame costs $250 and is currently available through ThinkGeek.