Siemens Siemens. OpenStage IP phones feature PC functionality; voice commands; and a TouchGuide interface that allows users to access contacts, conferencing, and speed-dial features. Because the phones are based on open programming standards that support Java, HTML, WML, and XML, there's more flexibility for adding third-party applications, such as “push” programs to get more caller information, the firm says. 800.310.6308.

Toshiba Toshiba. The Strata CIX IP platform lets users mix and match technologies so they can create a pure IP system or one that converges with their existing phone network. That means users can have one number that reaches their desk phone, PDA, or laptop, all with feature-rich capabilities, such as conferencing, call forwarding, voicemail, messaging, caller ID, and transfers. 800.222.5805.

Plantronics Plantronics. The .Audio 910 headset's multipoint technology lets the user switch seamlessly between Bluetooth-enabled Internet calls and mobile or desktop phones with the touch of a button, and without the need for multiple headsets. Users are not tethered to their PC, so Skype users can receive incoming calls while answering and ending calls remotely from the headset. 800. 544.4660.

Vonage Vonage. The V-Phone is a USB memory stick keychain loaded with software and VoIP technology that lets users take their phone number with them. By plugging the V-phone into a computer's USB port, a user can make and receive phone calls over a broadband Internet connection. The V-Phone can be programmed with the same number as the user's office phone. It works on Vonage's standard flat-rate phone plans. 800.980.1455.

Motorola Motorola. The T31 cordless phone can be used as a traditional landline phone or can connect users for free to Windows Live Messenger to make voice calls over the Internet, enabling VoIP functionality without a monthly service fee. For dialing non-Messenger contacts, the T31 has the option of a Verizon service plan, allowing the user to dial any number from anywhere, no matter whether they're connected to a landline or the Internet. 800.367.2346.