Skype users can now run the company's free voice-over-IP service with conventional cordless phones. But you do have to have one of Siemens' new Gigaset DECT phones.

Siemens and Skype have teamed up to make a nifty USB gadget that plugs into a PC, communicates with the DECT base station and routes Skype calls over the Internet instead of the phone system.

The Gigaset M34 USB adapter allows the Siemens phones to access features such as free calls to Skype users, buddy lists and conference calling. Skype, based in Luxembourg, has become a leading provider of VoIP by offering an IM client that includes voice software that allows users to call other Skype users free, as well as make cut-rate "SkypeOut" calls to non-users. The company says its free software has been downloaded 32 million times since August.

The Siemens adaptor is another application of Skype's recently released API (application programming interface), which also lets Skype users link to voice from their web pages. Skype hopes it is the beginning of a wave of applications built to integrate Skype.

The new adaptor costs about 99 euros, and works with Siemens' Gigaset C340/345, CX340/345isdn, S440/445, SX440/445isdn, S645 and SL440 phones. The company is testing the unit in other regions. The service is only available in the UK, Germany and other European countries.