For several years now, many PC users have been saving themselves a small fortune by using their PC to make VoIP calls instead of using the tradional telephone network (especially when calling internationally). PDAs together with the growth in WiFi coverage now allows this saving to be made while you are on the move. With the features offered by VoIP you can even take the same number used on your PC with you on to your PDA - you only need one contact number.

There is a huge selection of VoIP providers worldwide with very cheap rates when compared with cell phones; it is often free to call some destinations and many do not charge a monthly fee. Even international calls over VoIP can cost lower than 3 cents/min.

Articulation for PalmOS, from Hampton Software Ltd, offers users of Palm PDAs the opportunity to communicate on the go using the VoIP service of their choice.

Features:
- Ability to make PSTN calls with your PDA
- Select the SIP VoIP provider of your choice
- Lookup phone numbers direct from you contacts
- Touch-tones (DTMF) for 'phone menus'
- Supports WiFi, Bluetooth and EVDO connections
- Call timer
- Silence suppression (only transmit your voice)
- Echo cancellation for 'speakerphone' use

Technical Features:
- Secure account authentication with SIP MD5 Authentication
- Supports GSM and G711 codecs (GSM is suited to low bandwidth connections)
- NAT support through RFC 3581 and ability to fix ports for symmetric NATs
- Symmetric RTP support
- Low latency
- Low memory usage

Some features depend upon the VoIP service provider selected.

More Info: http://www.hamptonsoftware.co.uk/articulation/index.shtml