If you're an existing Skype user, you'll definitely find this offer useful. Right now, you can enjoy unlimited free worldwide calling for an entire month! Normally, calls to landlines or mobiles require Skype credit which involve fees and whatnot but, if you participate in the offer by November 15, you can enjoy those perks for no charge. Basically, you get to enjoy all the features of a paid Skype account at no cost.
The offer is only redeemable by Skype users who have had an account for more than 29 days and a fair usage policy applies. You will also be asked to enter payment details although that's only if you forget to cancel the service -- which is automatically extended if you forget. More details can be found here.
Offer must be redeemed by November 15.