The BlackBerry PDA device has been rumored to have addictive properties. Thus, we have the slang "CrackBerry." And apparently, lots of corporate users are hooked. Research In Motion (NYSE:RIMM), which makes the BlackBerry device, delivered a strong fourth quarter last night and described a promising year ahead, including an impending "breakout" in the coveted Asia Pacific region.

Research In Motion's fourth-quarter revenue increased 141% to $211 million. Net income came in at $41.5 million, or $0.46 per share, as compared to a loss of $31.1 million in the same quarter last year. If you take out litigation costs and a tax-recovery charge, pro forma earnings were $0.56 per share. It also upped its guidance for the coming year.

In addition, Research In Motion passed the 1 million subscriber mark during the quarter. It also said it plans a 2-for-1 stock split, which many of us know, in the grand scheme of things, is pretty ho-hum news for Foolish investors.

In its conference call (transcript courtesy of CCBN StreetEvents), Research In Motion described an environment where its BlackBerry is distributed by a who's who of wireless heavyweights, such as AT&T Wireless (NYSE:AWE), T-Mobile, Nextel (NASDAQ:NXTL), Cingular, and Verizon (NYSE:VZ), among many.

Continued penetration into international markets is seen as a growth driver, including the hoped-for invasion of China. So far, Research In Motion said that it sees BlackBerry success in the region with English-speaking users, such as expatriates and employees of multinational corporations. Though it has Chinese character support on the handsets, RIM says it still needs to work on implementing support of Unicode, a worldwide character standard.

While many may see the BlackBerry as the only game in town, Research In Motion faces some adverse forces, including a patent lawsuit. There are also its old rivals to contend with, under the palmOne (NASDAQ:PLMO) umbrella ever since the Palm Pilot maker took over Handspring, as well as emerging rival products. Investors might be relieved to know the company plans to increase its research and development spending, including boosting head counts, in the first half of the year.

It's difficult to get past the fact that this stock has shot up 62% over the year. It sagged a bit today, likely reflecting that the earnings weren't quite the rush investors were expecting. While it may not have delivered a huge upside surprise, for those who aren't adverse to risk, the possibilities of a largely untapped global market with an improving economic view are what make Research In Motion as alluring as its BlackBerry device.

Do you think Research In Motion can keep it up? Talk to other Fools about the issue on the Research In Motion discussion board.

Alyce Lomax, who is CrackBerry-free and never emails and drives, does not own shares of any of the companies mentioned.