You can now get an application from Verizon, "Do Not Disturb," that lets you block as many phone #s as you want. It also lets you block restricted or unknown calls (verizon's website doesn't let you do this). it's really good for blocking telemarketers. You can also set it up so people can't call you during certain times like early in the morning when you're sleeping . only problem is that it costs money but it's cheaper than the verizon website thing
it's also a lot easier to use once you got it installed because you can edit the list of blocked numbers right on the phone.
The easiest way to get it is to text "dnd" to "apps" (363 to 2777), or go look for it under Media Center or Get It Now . I think it's available for blackberry too!