**Update** According to MojoSavings, this was confirmed as 100% valid with AT&T, and you won't be charged anything! It's their way of saying Thank You!
If you have AT&T and free texting, you can text yes to 11113020 and get 1,000 Bonus Rollover minutes! I just did it and got this message:
"Thank you for accepting our free 1000 bonus Rollover minute offer. Please allow up to 4 weeks for processing."
You can also text this if you don't have free texting, but you will have to pay your standard texting charges.
Thanks, My Frugal Adventures!