Depending on whom you ask, handheld devices are either utterly necessary or a waste of money. There’s little middle ground, which suggests that if you have a genuine need, you should get one. If you don’t, don’t try to create a need.

We’ll limit the discussion to PDAs (personal digital assistants) and cell phones. A threshold decision is whether to get a device that combines both functions. Our advice is don’t.

Chances are you need one of the devices more than the other. “Look at the primary reason for the device,” advises Scott Ingram of Grey Matter Technology. “Do you want a PDA or do you want a phone? What’s the most critical? Is the secondary use as useful?”

Another factor is the price you pay if your combined PDA/cell phone dies. You lose both functions.

As with laptop computers, the value of handheld devices is directly proportional to the time away from the office for the people using them. For sales personnel on the go, a cell phone is a necessity. They range from the freebie phones given away when you sign up for a wireless account to $500 or more for full-featured Internet ready devices.

Be leery about Internet promises. Cell phone technology accesses the Internet at an agonizingly slow crawl, which is bound to frustrate more than facilitate.

Just as a sales rep without a telephone is silenced, a sales rep without contact information is crippled. The threshold issue for PDAs is whether road warriors can be better served with laptops.

Laptops offer advantages. They hold more information than PDAs. They’re easier to work on and have Internet access, via wireless or dialup. But there are disadvantages. A laptop can’t be used standing up or walking around. It doesn’t fit in purses or pockets.

Ultimately all PDAs will probably combine cell phone capability and wireless Internet access. Until then, prices range from less than $200 to more than $600 for features including color display, pocket software, built-in digital camera and keyboard. But even the vanilla versions are highly prized by those who use them.

Your task is to determine whether they’ll be used enough to be of value. As one consultant noted, 90 percent of her clients who purchased PDAs have reverted to their Daytimer paper systems.