MTNL has today launched BlackBerry services for its prepaid users in Mumbai. The state-owned carrier was earlier offering BlackBerry services only to its post-paid subscribers. MTNL prepaid customers can now subscribe to BlackBerry BIS Lite plan which allows unlimited free access to emails, BlackBerry Messenger (BBM) and other Instant Messaging services at Rs 251 for a month. Those who wish to access BlackBerry services for a limited period can opt for the BIS Lite trial plan which will cost just Rs 150 and w...