Hewlett-Packard has introduced its first mobile thin client, a notebook that can store data and access applications wirelessly on a centralized server.

In addition to the Compaq 6720t, HP introduced on Thursday two desktop thin clients, the Compaq t5730 and t5735. The 6720t and t5730 run Microsoft Windows XPe, and the t5735 uses the Debian Linux operating system and supports open source applications.

HP's thin-client hardware uses technology acquired last year in the $214 million purchase of Neoware, which sold hardware and software that allowed users to build desktop systems that could be centrally managed from servers with little desk-side intervention. Neoware's Linux-based thin-client systems complemented HP's Windows-based systems.

The 6720t mobile PC features a 15.4-inch display and is powered by a 1.06-GHz Intel Celeron M Processor 423. The machine also has 1 GB of memory, a 1-GB solid-state flash drive, and three USB 2.0 ports. For graphics processing, the PC uses the Intel Graphics Media Accelerator 950.

The mobile thin client has no hard-disk drive, since all storage is hosted on a server, which also handles processing for all business applications, such as Microsoft Office. The system supports Wi-Fi and has a PC memory card slot for connecting to 3G broadband wireless networks.

HP is marketing the new product to companies with workers who spend a lot of time outside the office, such as insurance claim processors, warehouse and inventory managers, and office administrators.

HP and other thin-client vendors claim their products are easier to manage and more secure than conventional computers because applications and data are on a server that's constantly in the control of IT staff. Rather than each employee using Office or other applications on the desktop, they're served the software from a virtual machine in a data center.

HP Virtual Desktop Infrastructure is built atop VMware's Infrastructure, which manages multiple VMware Server and VMware ESX Server virtual machines. HP adds its own management software, such as Consolidated Client Infrastructure, which centralizes PC processing operations in the data center, and HP Systems Insight Manager, which centralizes storage management.

Thin-client vendors have yet to make much, if any, headway in replacing traditional client computers. Part of the reason is cost. The client hardware for both systems is about the same, which means a thin client actually offers less technology than a conventional system, which has internal storage and more expansion options. For example, HP's new 6720t mobile PC, which is scheduled to ship by the end of the month, is priced at $725, and a Compaq Presario C700T notebook starts at $500.

As to the security and management advantages, most companies with conventional networks in place have yet to find thin-client computing systems worth the cost of replacing the old system.

Specifications for the new Compaq t5730 and t5735 desktops could not be found on HP's Web site. The machines, which HP said are available now, are priced at $499 and $450, respectively. Currently, HP is offering an older Compaq t5530 thin client for $300.