To the naked eye, a Voice over Internet Protocol (VoIP) phone resembles any other telephone or cell phone product. However, it's actually a phone product that allow users to place voice phone calls over a computer's Internet network instead of a standard telephone network; thus, the term "IP Phone," or Internet Protocol Phone.

Variations of mobile VoIP Phone products include:

• A standalone IP phone with hardware that resembles a standard mobile phone or analog phone product
• A Wi-Fi enabled mobile VoIP phone with hardware that resembles a mobile phone or a PDA; in the latter case, these types of PDAs may also be called smartphones (Besides Wi-Fi, other such IP phone network protocols may include SIP, or Session Initiation Protocol, and HSDPA, or High-Speed Downlink Packet Access)
• A mobile IP phone with fixed and mobile telephony convergence; i.e., the ability to switch between standard telephone/cell phone networks, computer networks, and other networks
• An Instant Messenger-enabled IP phone that supports communications from phone to PC and PC to phone

Mobile IP Phone enhanced features include:

1. Voice Mail
2. Speed dialing
3. Call waiting
4. Call hold
5. Auto Attendant – a feature that provides automated messages to callers and directs calls
6. Call forwarding, or Find Me Follow Me
7. VoIP phone operating systems include Symbian, Windows Mobile 6, RIM Blackberry, and iPhone OS, Linux, Palm OS

Action Steps
The best contacts and resources to help you get it done

Find VoIP telephone service provider product comparison resources

An Internet phone service provider with the right features for your business VoIP phone will sell or recommend the right IP phone product for your business.

I recommend: Voxilla.com provides product reviews for those looking into Internet phone service software for Internet phones. VoipReviews.org offers a long list of comparison reviews for VoIP service providers.

Visit VoIP service provider websites

Specific VoIP telephone service provider websites recommend compatible Internet Protocol phone products.

I recommend: T-Mobile offers "Unlimited Hot Spot Calling" Wi-Fi enabled Internet phones such as the Blackberry Curve and the Samsung Katalyst. Hutchison 3G UK Ltd. mobile media company offers service for its 3 X-Series Internet Phones made by Nokia.

Find a VoIP telephone compatible with your operating system

Some users prefer specific operating systems such as Linux and RIM Blackberry.

I recommend: Microsoft's Windows Mobile operating system (OS) website recommends Internet phones from Samsung, T-Mobile and AT&T. The Blackberry North America website recommends RIM Blackberry OS-enabled IP products. The Linux Online website recommends the Linux OS-enabled smartphone products, particularly the Nokia 770.

Get information on VoIP phones compatible with VoIP applications

VoIP applications offer specific features that may be compatible with your business needs.

I recommend: The Skype VoIP application offers its own 3 Skypephone product through UK mobile media company Hutchison 3G UK Ltd. Google Talk is Google's VoIP application coupled with their IM service. Visit the Google Mobile site to see Google Talk-compatible IP phones. Gizmo 5 sells its own phone product that works on its open source VoIP operating system.

Get product information on specific mobile IP phone system models

Nokia is one of the pioneers in IP mobile phone technologies. Apple's iPhone is also becoming a player.

I recommend: The Nokia E-Series and the Nokia N-Series Internet phones are among the prime movers in the development of smartphone technologies. VoIP applications for the Apple iPhone are available at the Apple iTunes App Store.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Keep track of news and views about phone product developments in fixed and mobile telephony convergence where phone products have access to both landline and mobile networks.
• •  When buying an IP phone system with a free or low-cost mobile phone service provider such as Skype, be aware of current litigation in governmental courts centered on conflicts between VoIP services and traditional telecommunication and cable companies.