How do you block someone from texting/calling your cell phone?

I have a Sprint Blackberry Curve, and there is a guy i know who has kind of gotten obsessed with me for some reason. I really, really want to block his number! I'm only a teenager and I don't want to change it just because of some creepy guy. So PLEASE help me figure out how to block someone's cell phone from calling/texting my own cell. Thanks!!! :))How do you block someone from texting/calling your cell phone?me too! except im a dude and its my ex lol. She's obsessed with texting me and i just ignore them but she still does it ALL THE TIME! My buddy told me yesterday you just call your carrier(mines at%26amp;t) so you would call sprint and just tell them you would like to block this number. make sure you have the number writin down on a piece of paper so you can tell them the number:) good luck!:)