I just learned from a blog that I subscribe to that you can share your free Amazon Mom 2-day free shipping with one other person for as long as your Amazon Mom benefits are valid. I had Amazon Mom benefits before but mine expired to I signed up DH. However, I don't like ordering things off DH's account because then he sees everything I buy :-)
So, I just logged into his account and "shared" his membership with me. Now I can get free 2-day shipping on all of my Amazon orders too. The only consideration is that if I order diapers or baby stuff worth $25 or more, I'll want to do it using his account so that it extends his Amazon Mom membership (thus extending mine). I hope that makes sense.
Here are the instructions with screenshots on how to do it: