On4 is the latest voice over IP (VoIP) service from a new company called On Instant. If you've heard of Skype, you'll be familiar with the idea - using secure peer-to-peer Internet connections to talk (or send voicemail or text messages) to other On4 users.

The free download is only about 6MB, so it's not too onerous to try it out, and registration requires only basic personal details.

After installing and logging on you see the main On4 screen, which is uncluttered and self-explanatory. You can search for contacts worldwide, or invite friends to join by email.

The privacy level can be set so that only contacts in your address book can call you, but if you're feeling adventurous you can let any On4 user get in touch.

Audio setup is poorly implemented at the moment - there's no built-in audio wizard and no online help - but On Instant told us that it's rectifying this side of things.

On4 works with any microphone/speaker setup or USB handset, but we had to fiddle about with Windows' audio settings to get our USB handset to co-exist with our PC's speakers. A human operator is always on hand to help you get started.

Voice quality is superb, with little discernible lag and none of the cracks and pops usually associated with VoIP traffic.

On4 is really an interim release - version 2 is imminent, with a totally revised client and extra services such as conference calling and, eventually, the ability to call landlines or mobile phones.

It?s free, so give it a try and see what you think. Business users should take a look at On Instant, a paid-for service based on the same technology.

Contact:On Instant (01534) 746533
www.on4.com

Specifications:

Price:
Free download.