EDGE isn't very fast? If you want better speeds than this, you basically need 3G. I'm not sure if Sprint offers this, specifically, and I'm also not sure which BlackBerry you have. Plain 8700xx models do not support 3G, but only GSM and enhanced flavors of such. The 8707 is compliant with 3G, to my knowledge, but again, I'm not sure if Sprint offers this service.
8700g. PIN: 23D5CBEB