Gadget geeks often don't need a justification for buying the latest tech device. They crave it; they buy it.
But frugal gadget lovers might need some convincing. They might be persuaded if the device actually saves them money or somehow pays for itself over time.
To that end, here are some fun rationalizations, however contrived and self-deluding, for buying a few of the coolest mainstream tech gadgets.
THE AMAZON KINDLE:
This is an e-reader, a device devoted to reading books, magazines and newspapers. Publications are delivered wirelessly to your Kindle for no additional charge. Savings come from two sources: cheaper reading material and free wireless service.
Kindle versions of most books cost about $10. Newspaper and magazine subscriptions are often cheaper than paper versions.
Assume that during a year you substitute two $25 hardcover books and four $15 paperbacks for the $10 Kindle versions. And assume you swap a Kindle subscription for the paper version of The Wall Street Journal at an approximate non-introductory price of $250 per year. Total annual savings: about $120.
Another source of savings is the Kindle's crude Web browser with free wireless service. It's tedious to surf the Web using it, but you can check Web-based e-mail and read a few news headlines for free. If that can substitute for a $20-per-month smart phone data plan, that saves $240 per year.
Those put you ahead $100 in the first year, including the cost of the Kindle.
You also will never have to rebuy a lost book. Kindle books are always available to download again. And you can use the Kindle's voice reader to read aloud some books, potentially substituting for audio-book purchases.
Alternatives: You can make similar arguments for Kindle competitors, such as the Sony Reader and the Barnes & Noble Nook.
Reality check: The public library has free books, publications and, probably, Internet access.
THE APPLE IPAD:
Price: $499 to $829
Depending on storage and wireless capability, the slate-shaped iPad has the functionality of a small laptop computer, without the physical keyboard. Its potential savings can come from being a laptop substitute, no-commitment wireless plans and similar book- and-publications savings to the Kindle.
Stan Steinreich, president of Steinreich Communications Group in Hackensack, N.J., figures he saves about half the cost of the five daily newspapers and 35 magazines he subscribes to.
Wireless plans for the iPads that can use them are exclusively from AT&T. They cost about $15 per month for 250 megabytes of data and $25 for 2 gigabytes. The plans can be canceled, restarted and changed month to month, which is a boon to infrequent travelers.
The iPad can also substitute for a music player, book reader, even a small television, given the amount of online TV content and availability of the Netflix software app. Free and low-cost apps can turn the iPad into everything from a carpenter's level to a Sudoku puzzle book to a hand-held gaming device.
Alternatives: You might make similar rationalizations for a netbook computer, scaled-down laptops made by a variety of manufacturers. Most are cheaper than an iPad.
Reality check: If you have a laptop and smart phone, where does the iPad fit into your daily usage habits?
Price: Varies depending on service plan, which costs up to $60 per month.
The MiFi is a credit-card-sized mobile hot spot. It provides 3G Internet access for up to five nearby Wi-Fi devices. Three people could be connected with a laptop computer, iPod Touch and iPad while riding a train, for example. A family on a summer road trip could all have Internet access in the car.
The most robust MiFi service costs about $60 per month through such providers as Verizon Wireless and Sprint. It could substitute for your home Internet access, though it's slower than a cable modem and has more limited range than a regular Wi-Fi router. (The plan has a 5 GB monthly limit, which should be OK unless you stream a lot of video and audio.)
The MiFi would eliminate the cost of paying for online access at airports and hotels. It could even help make cheap phone calls using Internet calling services. It might also be intriguing for iPhone and iPad users who are dissatisfied with being locked into AT&T service, which has well-documented problems with a sluggish network and spotty coverage in some regions.
Leasing a MiFi avoids a service contract. 3Gstore.com, for example, offers a MiFi with 5 GB of data per month and Verizon Wireless service for $50 per month and $90 for the device.
Alternatives: Some smart phones double as Wi-Fi hot spots. The iPhone now allows "tethering," using its service for laptop Internet access, but it costs an extra $20 per month.
Reality check: In many regions, finding a public Wi-Fi hot spot is easy. Even if you have to pay occasionally, it could be cheaper than a MiFi.