As cameras, MP3 players and text messaging become must-haves on cell phones, one startup is bucking the trend by going back to the basics.

Peek, a New York-based company, will soon launch a mobile device that has only one function – e-mail. In other words, the bare-bones gadget doesn’t take pictures, come with flashy graphics or even make calls. Given that you’ll still have to carry a cell phone, who would want to buy it? The so-called “soccer mom” demographic, says Amol Sarva, Peek’s founder and a former Virgin Mobile (VM) executive.

Sarva believe that middle-aged women with kids want to be able to access their e-mail while out and about, but don’t necessarily want all of the other fancy features packed into most smartphones. That’s why the device his company developed doesn’t do anything but e-mail. That’s also why it has soft, rubber keys specially designed for women’s fingernails. (Whether potential buyers will be attracted or turned off by such gender targeting is another matter.)

“The overwhelming temptation is always to add value by adding more features and functions into a device,” says Michael Gartenberg, VP of mobile strategy at research firm Jupiter Media. “But this philosophy of ‘less is more’ could be the correct approach for a more mainstream demographic.”

An estimated 14% of cell phone users access e-mail on their mobile device, according to research firm ComScore M:Metrics. But most of them are corporate employees who already have BlackBerries or other smartphones. Peek is hoping to attract a less tech-savvy crowd – the kind of people who don’t know their IMAP (a way of transferring e-mail from a server to a device) from their POP (another way to do the same thing).

Of course, to reach a more mainstream demographic, the price has to be right. The Peek (which comes in cherry, aqua and grey) will cost $100, with a flat monthly fee of $20. Sarva says the device runs on T-Mobile’s nationwide network, though customers won’t need to deal with the carrier. Even better, they won’t need to sign a contract. Peek will be sold in Target stores nationwide starting in mid-September, and customers will pay for the monthly service by credit card, either online or via the device, directly to Peek.

To start sending and receiving messages on the device, all they’ll need to do is enter their e-mail address and password (you can get up to three accounts on one device, including Gmail, Yahoo mail and AOL).

But will the Peek be a hit? Maybe, though it could be a hard sell for several reasons. Besides the challenge of finding an effective way to get the word out to its non-techie target demographic, Peek could face competition from ever-cheaper smartphones.

Devices like a Motorola’s (MOT) Q or Palm’s (PALM) Centro are now available for under $150, and they do a lot more than send e-mail. But Peek believes its target market doesn’t care about smartphones’ bells and whistles and don’t want to be tied to service contracts.