Very easy to activate. Costs Rs 450/- for the SIM. Shop around for a good number before you buy a phone. (You tend to settle for any number if you have just bought a new phone just to get on air). Insert the SIM into your phone and switch it on and you are ready to talk.
Very polite and helpful helpdesk staff. Call 567 for assistance. Call rates are Rs 3.50 per minute incoming and outgoing. Half rate at night. Free incoming from other BPL mobiles. STD and ISD comes as standard. I think you can get recharge cards for Rs 300, 400, 500 (one month validity) now, but they keep changing them every now and then. If you could manage with about 100 minutes per month (i do it all the time) it’s a great way to be mobile at just Rs 300-400 per month.
Good coverage in the cities but patchy on the highways (kerala), don’t know about other states.
If you have a Nokia or a phone with downloadable icons and tunes - the bplmobile.com site has plenty of stuff.