VTech Communications wants to put an end to this mad phone dash with its new $150 Expandable Cordless Phone System with Bluetooth, the LS5145. This device synchronizes with your cellphone and redirects incoming cell calls to ring wherever the VTech phones are placed in the house. It works with your landline and up to two Bluetooth-linked cellphones, and can be expanded using additional handsets that cost $80 each.

The $150 Expandable Cordless Phone System with Bluetooth from VTech Communications Inc.

The concept of a cellphone extender isn’t new, but not many of them have caught on. Another popular add-on to cellphones at home is the repeater, which focuses on boosting a phone’s signal in a place with poor coverage. The VTech 5145 could work as a repeater, assuming you put it and the finicky cellphone in a place with good coverage. But if your entire house has lousy cell coverage, it won’t work as a repeater.

AT&T licenses its corded and cordless phones through VTech, which sells a less-expensive product similar to the 5145 called the AT&T EP5632. It costs $100 and has the same basic functions as the 5145, but is clunky and much less stylish. Its additional handhelds cost $60 each.

This week, I put my feet up and tried the VTech 5145 and one of its accessory handsets, the LS5105. These phones are stylishly thin and have bright color display screens, which can be set to one of 27 still color wallpaper images or four animated designs. It took me only a minute to pair cellphones with the system using Bluetooth, a wireless technology that connects devices that are within about 30 feet of one another. And the VTech’s primary function — extending the cellphone throughout a house to make it more convenient to answer — worked well, ringing much louder than my cellphone.

But the 5145 didn’t display the numerous names and numbers stored on my cellphone’s contact list. Unless I wanted to painstakingly enter the data into the VTech, incoming calls were only identified with phone numbers, so I rarely knew who was calling. And I could only call the handful of numbers that I know by heart.

Bluetooth technology isn’t incapable of transmitting data: My BlackBerry Curve even tried to transfer its contacts to the 5145, but couldn’t. VTech chose to use headset Bluetooth synchronization on the 5145 rather than hands-free synchronization. Hands-free is the same technology used in most Bluetooth-equipped cars; it provides more access to the Bluetooth device, such as phone-book integration.

I also missed other features on my cellphone when it wasn’t by my side, such as text messaging and voice mail. Incoming text messages were sent to my cellphone unbeknownst to me since I wasn’t near it, and when I didn’t answer incoming calls through the VTech, I had no way of knowing if the caller left a voice mail on my cellphone.

The 5145 includes a base station and primary phone; the 5105 additional handset includes a small stand just big enough to hold it upright. I set up the base station near where I drop my work bag after coming home each night. After the initial pairing during setup, phones automatically link to the VTech, meaning I never had to take my cellphone out of my bag.

I paired the 5145 with two phones at once: a Motorola Razr using Verizon and a BlackBerry Curve with AT&T service. I also tested pairing a third phone with the system, the HTC Pocket PC 6800 from Sprint, though only two cellphones can be paired simultaneously. Just one of the Bluetooth phones can be used at a time, in addition to the landline. As long as the two paired phones stayed within about 30 feet of the base station, they automatically started routing calls through the VTech.

Call waiting worked like using my actual cellphone, except I pressed different buttons on the 5145 to “swap” calls. If you’re chatting on a landline call, you can answer an incoming cellphone call by placing the landline call on hold. If each line — landline and cellular — has call waiting, a total of four callers could potentially be linked to the VTech system at once.

In my house, we gave up our landline years ago, so I tested the system using only cellphones. I saved myself a few trips racing up and down the stairs to find where I had left my cellphone, instead placing the base station on one floor and the additional handset on the other. Using cordless phones for the first time in years reminded me of the issues that accompany this system. The line became fuzzy when I moved too far away from a phone’s base station, though VTech says a connection can stay clear for up to about 900 feet.

I almost forgot that cordless phones can’t be taken out of the house. While on a phone call, I had to stop myself from heading out the front door and continuing my chat as I walked to the corner store. Cellular calls that are in progress on VTech handsets can be continued on the cell by adjusting a setting on the cellphone, or by walking far enough away from the base station to receive a cellphone prompt to disconnect from the system.

I made calls from the handsets by first choosing which of the paired cellphones to use. My calls were received by friends and family just as if I was calling on my cellphone, though a couple of people told me that the connection didn’t sound quite as good.

Each handset is equipped with a speakerphone, and missed calls are noted on the color screen and in a call log, along with the date and time. A built-in intercom system lets handsets communicate with the other or the base station. Users can choose from one of 23 ringtone-like melodies; I chose a steel drum tune for one handset.

If you’re looking for an easier way to answer your cellphone whenever and wherever it rings, VTech’s system might be a good solution for you. But if you rely on your cellphone’s address book to identify callers and aren’t up for inputting these data again, it might be worth waiting for a Bluetooth cordless phone system that will automatically copy data from your cellphone.

Edited By Walter S. Mossberg

• Email mossbergsolution@wsj.com