The phone goes for $295 directly from Helio on its Web site and few store locations. The MVNO (mobile virtual network operator) plans to extend Ocean’s availability to third-party outlets later this month.

Ocean offers full over-the-air music downloads, video-on-demand, a 2.4-inch, 260K color high-resolution QVGA display, a 2 megapixel high-resolution camera, a microSD slot, 200MB of internal storage, an HTML browser, MySpace on Helio, GPS-enabled Google Maps for mobile, Buddy Beacon and other features. The PlaysForSure-compatible handset promises an excellent 15 hours of music-listening on a single charge.

Its integrated messaging dashboard includes access to multiple public e-mail services and also incorporates Instant Message access through Yahoo Messenger, AOL's AIM Service and Windows Live Messenger.

Ocean measures only 21.8 millimeters thick, impressive for a dual-slider. And it weighs a mere 3.17 ounces.

Launched last spring, Helio, a joint venture between Earthlink and South Korean mobile operator SK Telecom, is named after Copernican's 16th Century Heliocentric theory of the Sun as center of the universe. As a brand, it is supposed to conjure how central mobility - the mobile phone in particular - is in young people's lives.

Helio also targets tech-savvy 18 to 34 year olds through its partnership with the mega-social-networking site MySpace. It currently has fewer than 100,000 subscribers—a drop in the bucket compared to mobile operators like AT&T, Verizon Wireless, T-Mobile and Sprint, all of which sport tens of millions of customers.

Unlike these and other traditional carriers, Helio - as an MVNO - doesn't own a physical cellular network. Rather, it rents and resells spectrum from these 'real' wireless operators as its own voice and data services.