Motorola's Moto Q smart phone will be compatible with the Napster To Go portable-subscription music service, Napster said yesterday.

It’s the latest device in a growing list of Windows-based phones becoming available that work with its service, the company said.

Moto Q's compatibility seems to be generating particular enthusiasm. The company says it expects Moto Q to be available in the first quarter of next year. The thin, QWERTY phone, will operate on Windows Mobile software and will offer email access and multimedia capabilities. The phone itself will feature thumbwheel navigation.

Napster To Go has also caught the attention of a variety of smart-phone vendors. They are lining up to offer phones compatible with the service, which allows subscribers unlimited access to Napster's song catalogue, with more than 1.5 million tunes for a monthly fee. Napster To Go will work with phones from Siemens, Orange, Hewlett-Packard and Audiovox Communications, as well as with phones from numerous other vendors.

Napster launched its mobile service in February and within weeks raised its fiscal quarter revenue guidance by $1 million on the strength of it. However, the service has been criticized for the dearth of compatible MP3 players, although that is expected to change over time as vendors release updated players.