BSNL, the only PAN India 3G Data Service provider is responding to Airtel's 3G Data Tariff cut with FMC by sweetening the offer further.

New BSNL 3G USB Dongle / Data Card Offer with CASHBACK
You'll have to purchase the 3G Data Card / Dongle and subscribe to any 3G plan worth more than Rs 400, the cost of the data card will be refunded back you as CASHBACK in 8 Monthly Bills.

BSNL 3G FMC Plan
Tariff - Rs 450
3G data usage - 3GB / Month [Airtel offers 4GB of Data over a period of 90 Days]
Validity - 2 Months
After this you'll have to choose any of the regular plans.

Glad that a state owned company like BSNL was quick to retaliate with a better offer and stay as the cheapest 3G service provider in India.