BlackBerry users were no doubt unnerved this week by a Supreme Court refusal to hear an ongoing case between the device's maker, Research in Motion, and NTP, a patent-holding firm. The court's decision may bring America's thumb-typing enthusiasts one step closer to a dead-stop shutdown of BlackBerry's wireless e-mail service, which boasts some 3.6 million U.S. subscribers.

So what's a jittery, BlackBerry-dependent owner to do if RIM is forced to shut down its network, even temporarily?

Chat-room discussions are alive with possible contingency plans -- from simply switching providers to complicated scenarios like purchasing service in Canada and paying roaming charges for use in the U.S.

In fact, the outlook isn't so bleak -- at least for one group. While larger companies generally run e-mail off the BlackBerry Enterprise Server, smaller companies tend to use RIM's redirector to pull POP3 and other common types of e-mail onto their BlackBerrys, says Avi Greengart, principal analyst for mobile devices at Current Analysis, a Washington, D.C.-based market-research firm. These smaller companies, he adds, are in a stronger position should BlackBerry be forced to discontinue its wireless e-mail service.

Redirectors are much easier to swap than servers. In this scenario, you may simply choose another company's redirector to route your e-mail to a different wireless device. Another easy alternative is to use Google's Gmail Mobile, which lets you forward any e-mail to a Gmail account, then view it from an ordinary cell phone -- no BlackBerry required.

No matter which alternative you choose, the switch can be made relatively quickly and with minimal disruption. Not so if you are on the server. In this case, Greengart says, the solution would be considerably more painful -- and expensive. Though companies like Good, Visto, Microsoft, and Nokia now offer devices with capabilities similar to RIM's, companies plugged into the BlackBerry Enterprise Server might incur hefty server license fees and be forced to make big infrastructure changes should they need to swap technologies.

The bottom line is, a business world without BlackBerries could put a crimp in some companies' style. Those who rely heavily on their BlackBerries for mobile e-mailing are likely to find the market newcomers simply not up to par, says Todd Kort, principal analyst at Stamford, Conn.-based Gartner. Not only does RIM have a several-year head start on other companies, but the BlackBerry also has the advantage in terms of security, manageability, keyboard design and price, he says. "RIM is the only end-to-end solution -- the device, the network, and all the middleware in between," says Kort. "There are alternative solutions, but they're all piecemeal."

Tessa Barrientos, owner of two Curves franchises in the Dallas area, is content to play Russian roulette with her e-mail service, for now. She says not only do she and her husband use the devices to stay in touch with employees and other franchise owners when they're out of the office, but the walkie-talkie function also gives them an inexpensive way to keep in constant contact with family, friends, and a franchise they recently started in Mexico City. "I hope it's not going to happen," Barrientos says. "I really run my life and my business with my BlackBerry."

If and when a BlackBerry, or any other technological shutdown appears imminent, Gene Fairbrother, lead business consultant for the Dallas-based National Association for the Self-Employed, recommends taking a proactive approach in informing clients. "It's not different from anything else in business," he says. "If you're going to move to another service, you don't want to wait until two weeks afterwards to let people know where you are."

For starters, Fairbrother says, be sure to give clients a backup e-mail address where they can reach you well ahead of time. "I'd much rather be upfront with clients that something may happen rather than having something happen and then trying to play catch-up," he says.

Meanwhile, experts say there's no need for such drastic measures just yet. The U.S. Patent and Trademark Office has already preliminarily rejected all of the related NTP patents twice, and final rulings are expected within weeks. While that initially had some analysts convinced that RIM was likely in the clear -- because the case would be thrown out altogether, or if not, the company could create a "workaround" -- the Supreme Court's refusal makes the outcome less certain.

For now, aside from formulating a technological backup plan, the best approach may simply be to wait and see how things pan out -- especially for potential new users considering a move to BlackBerry. But for those whose corporate psyches are intimately tied with their BlackBerrys, the waiting game is not so simple, either.