If you're looking to purchase a BlackBerry, there are several form factors you get to consider (unlike the iPhone) and it's certainly worth shopping around for. Of course, each carrier offers a different line up of BlackBerry SmartPhones, so consult online to find out which cell phone carrier offers which models of BlackBerrys.
All BlackBerrys offer a keyboard, either a full QWERTY, 20 key, or virtual keyboard, come with software to sync with your computer, and require a data plan with all US cell phone carriers. Currently the line up looks like this:
AT&T: Bold (9000 and 9700), Curve, Curve II, and Pearl
Sprint: Tour, Curve, Pearl II.
Verizon: Storm, Tour, Curve, Pearl
T-Mobile: Curve (8900 and 8520), Pearl, Flip.
These lineups are current, but of course, subject to change.
Picking a BlackBerry really depends on what you consider to be your perfect phone. Do you want something slim and pocketable? Try a Pearl or BlackBerry Flip. Do you want a bigger screen but still want an actual keyboard? Curve, Curve II or Bold. Bigger screen than those, but are OK with a virtual keyboard? BlackBerry Storm
Take the time to visit each provider and see which phone fits the best, and shop around online for the best deal in a cell phone.

