Nokia introduced Skype Internet-calling software for its N800 Wi-Fi tablet on Wednesday, providing another alternative to using a cell phone, while a debate in the U.S. over what networks such devices may be able to use in the future heated up.

When the N800 was introduced at the International Consumer Electronics Show in January, Nokia and eBay's Skype division said they were working on including the popular software in the device. Nokia delivered it on Wednesday with an upgrade to the N800's software. Current owners of N800s can download the software from Nokia's site.

Skype, with a claimed 196 million registered users, has expanded from its roots as a popular PC-based free calling system and offers text messaging, video calling, and low-cost dialing to and from traditional phones. There are already Skype clients for mobile devices and even some cellular smart phones, but some mobile operators try to block VoIP calls because they can eat into their voice business.

Unlike the Apple iPhone -- available in the U.S. only through AT&T -- the N800 doesn't have cellular connectivity, only Wi-Fi and short-range Bluetooth technology. So the device can access the Internet in a home or office, at a public hot spot, or on a municipal Wi-Fi network, but not in the vast areas covered by cellular data networks. The N800 is available at retail stores and Nokia's Web site for a list price of $399.99.

eBay is among a group of companies calling on the U.S. Federal Communications Commission (FCC) to encourage more competition against incumbent mobile operators when it auctions off prime radio spectrum in the 700MHz band. FCC Chairman Kevin Martin is advocating setting aside part of the spectrum for a network that would allow use of any application on any device, getting away from carriers' limited handset offerings and "walled gardens." But Skype's parent has joined consumer groups in calling for rules that would force spectrum holders to sell access to their networks wholesale to competitive service providers.

In addition to the Skype client, the new software version includes an Adobe Flash 9 Web browser plug-in and lets customers use larger capacity memory cards up to 8GB. The N800 has slots to accommodate SD (Secure Digital), MicroSD, MiniSD, MMC (MultiMedia Card) and Reduced-Size MMC cards. The Linux-based device also has a built-in camera and an on-screen touch keyboard and uses the Opera browser.