[TurboFool]

This actually has nothing to do with the phone, itself. It's a service on the carrier's side. I believe you can log into your sprint.com account and purchase and apply them from there. But it's all done on Sprint's end while they're routing the call to you, so the phone never relates to this process.

EDIT: Well, my explanation of it having nothing to do with the phone (technically) still stands, but I wasn't aware of Sprint's stubbornness on this subject. Thanks for the link, esqueue. Reminds me of when Sprint refused to put Picture Mail on the Mogul because it was a "business" phone. Who are they to decide how we're going to use our phones? I'm paying for it, so why can't I spend this much money on a "business" phone for personal use? And besides that, don't business people have friends and family?