Just for general information......Airtel has an annual package for BIS users @ 6999/-
It includes unlimited browsing + email.
This plan is not advertised, but if you write to BB support, they should help you out.
Actually, I am on a corporate plan with Airtel, so am not sure if this is offered to everyone.
But Vodafone has an annual pack at 6499, which is for personal users too.
Taxes additional and I am talking about the Mumbai circle.