There are several phone models that Verizon won’t sell you unless you buy a monthly data plan.
This is the very cheapest monthly data plan that you can buy.
Consumer Reports’ related blog site, Consumerist.com feels that this is a bad deal for the customer, designed to lure people in with a low price and then get them hooked so that they will upgrade to a more pricey data plan:
http://consumerist.com/2010/01/verizon-introduces-mandatory-999-3g-data-plan.html