Research In Motion’s BlackBerry Bold was finally launched today by AT&T. The high-end smartphone costs $300, after a $100 mail-in rebate and a commitment to a two-year voice and data plan.

The Bold is locked on AT&T networks and can be only operated in the United States. Its 3G service over HSDPA is available in 320 cities. The BlackBerry Bold can be purchased nationwide in AT&T stores, Best Buy online stores and from the company’s Web site. Best Buy is selling the Bold contract-free.

The BlackBerry Bold 9000 is RIM’s first headset that offers high-speed 3G connectivity. The device was first scheduled to be released in summer, but it was delayed due to some software issues and problems with battery life.

The smartphone offers standard BlackBerry functions like voice, e-mail, messaging, organizer and browser but will also delight users with its lustrous black exterior, satin chrome-finished frame and a leatherette back plate. The Bold features a weaked-up QWERTY keyboard with new thin metal dividers between each key, a half-VGA color display screen (480x320) which is a visual playground for the device’s 624MHz mobile processor, optimized Web browser, built-in full GPS, Wi-Fi, and a 2.0 mega pixel camera that features 5x digital zoom.

The BlackBerry Bold has 1GB of onboard memory and can support up to 16GBs of expanded memory via a microSD/SDHC slot. The phone also offers a sophisticated multimedia player, Bluetooth 2.0 support, Speaker Independent Voice Recognition (SIVR) for Voice Activated Dialling (VAD), 802.11a/b/g WiFi, and compatibility with more than 60 international 3G networks.

RIM is also preparing the release of other high-end devices such as the BlackBerry Pearl Flip 8220 from T-Mobile and the BlackBerry Storm from Verizon Wireless. The latter will be RIM’s first ever touch screen device and a fierce competitor for iPhone 3G and the G1.