A BlackBerry can do everything that a cell phone can do, including sending text messages via SMS. It's also an organizer, a calendar, an e-mail client, a Web browser, a two-way pager and a palm-top computer. Although it can do some of the same things a computer can, it doesn't have to be in a WiFi hot spot to work — it uses the cell phone network as well as 802.11b WLAN. It also have facilities like GPS, O.S 6.0, Google Maps And it also have its own Messenger, Well-Known to world wide, Named blackberry messenger.
Basic knowledge of Blackberry Hardware.
To be honestly speaking that, what you write this post. All are absolutely right and true. But at the end why you want to know this question, I am not understood. It is Blackberry Bold. I want to add something here. As my thought that people are using Blackberry for the only main reason is Mail service. Because, for mail service you need computer, Internet connection, and Server access for Receive and Send mail. Only for mail send there is a restriction for all worldwide servers.
For this service if you use blackberry, you are hassle free. Anywhere in the world if you have Blackberry then not need to use computer, or modem or WiFi Connection for this. Also you can Browse and use Blackberry Messenger as well.