Snapfish has a great deal going on where you can get 100 prints shipped to your door for just $5 with promo code STPATPRNT.
If you already have credit in your account for free prints then you will need to order that many as well in order to make this offer work. For example, if you have credit left for 10 free prints, you will need to order 110 total.
Go here to get started and if this is a new account, you will get 20 more free prints (120 total)!
This offer expires March 20, 2011