You won't believe it, but Airtel is actually surprisingly us day by day. They just released a special code titled "SPECIAL PRIVILEGE". THIS code gives a total of 6Gb for just 1500 naira. To subscribe, dial *440*161# It will last for 30 days and usable on all devices like Blackberry, Android, Java phones and even PC.What are you waiting for, start subscribing now b4 it ends because I don't think it will be available for life.
NOTE: IT only works on selected Sims. make sure you are eligible before subscribing.
Kudos to Airtel and I hope other network emulate them.