The two companies are now offering a line of no-contract phones using the network of Cricket, a division of Leap Wireless.

Starting Small on Devices

Off the bat, the companies are offering two low-cost devices made by Chinese manufacturer Huawei, the Pillar and Mercury Ice. The latter is an Android 2.3-powered smartphone available for $149.99, while the Pillar is a feature phone available for just $39. RadioShack promises that it will later offer "some of the hottest smartphones on the market."

A feature-phone plan including 300 minutes with unlimited texting and Web/data runs $25, while a 1,000-minute plan is $35. The smartphone plans are $50 for unlimited voice calls and text and one gigabyte of full-speed 3G data, or $60 for 2.5 gigabytes. After the plan limit, data speed is throttled.

The Mercury Ice, with a 4-inch display, 1.4-gigahertz processor and 8-megapixel camera, is available exclusively to RadioShack customers for 30 days, as of Wednesday.

"As a leader in the mobility category, RadioShack knows that each consumer is looking for something different when it comes to their mobile phone, and RadioShack No-Contract Wireless is part of our promise to continue to evolve in the wireless space to meet those needs," said Allen McClard, vice president of mobility for RadioShack Corp.

To sweeten the deal Cricket is offering its Muve Music service for RadioShack smartphones with unlimited downloads at no extra cost. The company said an 8-GB SanDisk expansion card will be bundled with all no-contract smartphones, allowing up to 6,000 songs as well as photos and video to be stored.

It's the second big foray into the wireless arena for San Diego-based Cricket Communications in recent months. In May, the company started selling the first prepaid version of Apple's iPhone in the U.S. via its stores and select dealers, for $55 a month for unlimited talk, text and data.

Fort Worth, Texas-based RadioShack also sells devices for other carriers, including AT&T , Sprint, Verizon and Virgin Mobile.

Making headway in the crowded wireless market dominated by the big four --Verizon Wireless, AT&T, Sprint Nextel and T-Mobile -- is a tall order. Those carriers as well as such smaller rivals as Metro PCS and Virgin Mobile also offer unlimited plans for those who want to avoid a two-year commitment.

Non-Contract Segment Growing

"It will be a tough go of it as there are many new and established [mobile virtual network operators] available already," said Kirk D. Parsons, an analyst for JD Power and Associates.

"But the non-contract segment continues to grow and the ability to immediately leverage the RadioShack retail presence are all advantages working in their favor."

Research from the NPD Group last month showed that prepaid, no-contract plan volume in the U.S. grew 91 percent in the second quarter compared with the same period last year.

Mike: