I enjoy getting mail, and there are many parenting magazines that offer free subscriptions from time to time. Right now I get Family Fun and Parents for free. The following are offering subscriptions for free right now:
Babytalk
American Baby
I'll let you know if I come across any others. I enjoy these for the information, but also the pictures which I cut out to make books for my son (such as the Baby Body Book and Baby's Book of Animals.)