Creddon - Tweet for a cause and a sponsor will donate $1 to charity
Mailjoy - Delightfully easy direct mail marketing. A DIY direct mail tool created for marketing and growth teams. Design, mail & track personalized direct mail postcards and letters. Digital marketers use Mailjoy to send data-driven mail campaigns.
Send Mail Get Mail - A postcard-sending website.
Felt for iPhone - Handwritten cards for the modern world
Postacard - Text a photo to send it as a postcard for $3.
NanaGram - Text your photos and we'll mail 4x6 prints to your Nana.