BlackBerrys and Bluetooth share an embarrassing trait -- these two uses of wireless technology have remained stubbornly irrelevant to many mainstream users, despite the benefits they might offer and the hype they often get in the press.

Many busy executives have become utterly dependent on the always-on e-mail access provided by Research In Motion Ltd.'s BlackBerry handhelds, but these devices' high costs and business-oriented features haven't constituted an attractive bundle for people who mostly use their cell phones to talk.

In a similar manner, Bluetooth has drawn a fervent following among enthusiasts who use it to link their phones to headsets, computers and even cars -- but it has remained invisible to customers of the nation's largest carrier, Verizon Wireless, which until recently did not carry a single Bluetooth phone.

These two technologies, however, just got another shot at breaking out into the mass market. RIM's new BlackBerry 7100 is the first BlackBerry that looks and acts more like a phone than a palm-sized computer, thanks to a crafty little keypad that works for both dialing numbers and entering text. Motorola's V710, meanwhile, finally brings Bluetooth to Verizon customers -- along with such high-end features as a built-in camera, camcorder and MP3 player.

The 7100, sold by T-Mobile for $300 (with a $100 mail-in rebate available), is easily the more remarkable device. At first, it looks as if it uses a painfully miniaturized keyboard in the usual QWERTY layout. Not so; the phone has a standard numeric keypad, plus a column of keys on either side. Most of the keys bear two letters apiece.

To free you from the awkward process of having to press a key twice to get the second letter on it, the 7100's SureType software looks at the words you could spell with any given series of key presses, then offers the likeliest match. For instance, if you press 8 (B, N), 3 (U, I) and 2 (T, Y) in order, SureType will suggest the most common word those letters spell out, "but." Other possibilities -- "buy," "bit," "nut," "nit" -- appear below for you to select with the 7100's jog-dial control.

This is the same concept behind the predictive-typing software on other phones, but here you can type on a keyboard layout that feels familiar.

The trick is to avoid constantly looking at the screen as you type, or you'll be too distracted by the alternate spellings. Just bang away at the keys, and most of the time SureType will be uncannily accurate -- it's even smart enough to add an apostrophe when you type "theres" or look into the phone's address book to see if you're trying to type somebody's name. I had few problems instant-messaging with a friend.

Sometimes I did have to enter a word manually, and in a few cases SureType offered some out-of-left-field spellings. But overall, it's an amazing piece of work. It's the best idea in handheld text input since the Graffiti software on Palm handhelds.

If only the rest of the 7100 was as smart as this. RIM's software, the weak point in earlier BlackBerry handhelds, hasn't gotten much stronger on this model. Although the 7100 includes the same type of address book, calendar, to-do and note-taking programs as Palm or Pocket PC handhelds, it's not close to competing with them -- thanks to RIM's unwillingness to learn basic principles of interface design.

The 7100's control menus are clogged with irrelevant and confusing options, it's too easy to lose data or settings, and even such basic actions as adding an appointment to the calendar take too many steps.

The Web browser included on this phone can display standard Web sites, but it frequently hangs up while trying to download their content. Like other BlackBerry devices, this one can access your e-mail -- but RIM has yet to offer non-business users the option of turning off mail delivery. As long as the 7100 is on T-Mobile's network, your e-mail will keep piling up in your inbox, whether you care to read it or not.

The 7100 ships with Windows-only desktop software to synchronize the 7100's applications with Microsoft Outlook and a few other applications via a USB cable. The Bluetooth on the 7100 -- a first for a BlackBerry -- does not allow data transfer between computers; the only thing I could do was use a wireless headset.

And that brings me to the Motorola V710. Verizon, having decided to offer Bluetooth for the first time, made the same mistake as RIM, but much more so -- it went out of its way to take away Bluetooth capabilities.

Specifically, the V710, sold by Verizon for $300 with a one-year contract, can't use Bluetooth to synchronize its address book with the one on your computer, nor can it transfer files to and from your computer -- even though Motorola built in both features.

Instead, the V710's Bluetooth support is limited to allowing a connection to a computer as an external modem -- a task so poorly explained by Verizon's documentation that I resorted to a Google search for help, which turned up usable instructions in somebody's weblog -- and linking the phone to Bluetooth headsets and hands-free kits.

Brenda Raney, a Verizon spokeswoman, said the company will release a software update that would restore address-book synchronization, but she did not explain why that feature got cut in the first place.

File transfer, however, won't be added, even though that would be the simplest way to move pictures and video taken with the V710 to a computer. Why? Verizon is afraid people would steal the downloadable programs sold through its "Get It Now" service.

But if people want to use Get It Now programs without paying, they can link the phone to a computer with a cheap USB cable and transfer all the stuff they want.

This is an embarrassing debut for Bluetooth on Verizon. Much like the woeful software on the BlackBerry 7100, it risks turning off newcomers to the technology entirely. That would be a sad waste, but the wireless industry works like that sometimes.

Living with technology, or trying to? E-mail Rob Pegoraro at rob@twp.com.

BlackBerrys and Bluetooth have fervent, but still limited, followings.