Postacard - Text a photo to send it as a postcard for $3.
Voodoo Manufacturing - Fast, affordable, high-volume 3D printing
Felt for iPhone - Handwritten cards for the modern world
Printful Integration with eBay - Sell products on one of the world's leading marketplaces
NanaGram - Text your photos and we'll mail 4x6 prints to your Nana.
Mockupify - Automate your print-on-demand product creation process