It seems like almost every month I log into MySprint account there's a new code for a free ringtone, or wallpaper, or multiple freebies. If you have a Sprint account I highly recommend getting yourself setup online. I will start a thread for freebie codes, as sometimes they disappear from their site before expiring, so if you missed a month you may, I repeat MAY, be able to use a recent one.
Promocode education page
Codes:
May : Free Ringer : INSTINCT
June: Free Ringer : MiniFlip
Make sure you click "Buy With Promo Code" to use the promo code...clicking on the other Buy button is an instant paid purchase. Also, the "free" aspect is delayed by a month or so, which means you'll probably get billed for it on the next cycle, then receive a credit on the cycle after that. A little strange loaning my phone company money...but they are Sprint!