TextBuyIt, a recently launched shop-by-cell phone service from Amazon.com Inc., seemed like the ultimate comparison shopping tool _ perfect for an unabashed bargain hunter like myself.

As it turns out, TextBuyIt is fun to play with and useful for getting deals on some products, but the service's limitations will likely make people wary of substantial purchases. Even for cheaper items, shipping costs will probably make many people think twice before text-buying.

The service is easy to set up on a cell phone or at Amazonpayments.com. Purchases through TextBuyIt are charged via the payment method that you select in Amazon's "one-click" checkout feature, and product deliveries go to the address you register there.

After the setup, TextBuyIt is pretty simple. If you're in a store and want to compare prices on something that seems appealing, you can text the item's name or bar code number to "262966," which corresponds with "AMAZON" on the phone keypad. Then the service sends back matching items available for sale on Amazon.

In order to buy something from Amazon, you just reply with a text message listing the number of the item you want. Other commands are possible, too, such as "M" to get more item listings, or "D" coupled with a product's number to get information like a product's rating on Amazon, and the availability of free two-day shipping for members of the Amazon Prime service. Generally, items over $25 include free standard shipping for non-Prime users, and TextBuyIt can tell you this, as well.

I got the most out of TextBuyIt at book and music stores, where I enjoyed roaming the aisles and comparison shopping on my phone.

At a Borders store, I looked up a book I had been wanting to read _ "The Billionaire's Vinegar" _ and found it was significantly cheaper through Amazon ($16.47) than at the store ($24.95).

I sent TextBuyIt a command indicating I wanted to buy the book, and then got the requisite recorded phone call from the service, letting me confirm or cancel the order. After I confirmed the purchase, TextBuyIt sent me a text message thanking me and giving me the purchase price and shipping cost.

A few days later, the book arrived at my apartment, well worth the wait since I'd saved some cash.

Several other times, though, I looked up potential purchases like CDs and earbuds and found that the Amazon prices matched brick-and-mortar store prices, or were only a little cheaper.

In the case of singer Duffy's "Rockferry" CD, also at Borders, I figured it was worth making my purchase at the store instead of through TextBuyIt, simply because the prices were too close _ $10.99 at Borders compared with $9.99 on Amazon, at the time _ to justify paying for shipping.

And when there wasn't a big base price difference, I found myself thinking more about my desire for instant gratification, and how I really didn't want to wait for a few days to listen to a new CD.

Presumably, this desire could lead some shoppers to ask brick-and-mortar merchants to match prices they discover through TextBuyIt. Good luck, though. I tried this with a digital voice recorder at an electronics store and was rejected by an apologetic salesman.

Though I did look up some more expensive items like digital cameras and iPod docks, I wasn't able to find matches for several products I saw in stores and wanted to compare prices on, like Tivoli's iSongbook and Bose's SoundDock.

That happened because TextBuyIt reveals only items that Amazon sells directly, which means that things sold by third-party merchants are unavailable.

Another problem with TextBuyIt is the lack of live help. There is no way to contact an operator for TextBuyIt purchases, so users who aren't getting the results they want via text message can't just call the service to sort things out.

And don't expect to get many answers via text. If you text the service an "H" for "help," it will respond with a list of service commands and the Amazon Payments URL _ not so helpful when I'm standing in a store and don't have my laptop in front of me.

I probably won't be text-buying my next major purchase. I'm still beholden to the images, details and deals I get when shopping on the Web proper, and the satisfaction I feel walking out of store holding a new gadget or outfit.

But chances are, next time I'm at a bookstore I'll be holding a best-seller in one hand and my cell phone in the other, texting to figure out the best deal.