A new release of the Firefly technology recently launched and announced here at Kolabora is just out of the door again.
Firefly is a new tool that may indeed attract a lot of attention from both users and the industry as a whole. Firefly, bridges with elegance the barriers between instant messaging and VoIP, just like Skype did. FireFly adds to its offering an upcoming direct bridge to standard telephone lines with very low prepaid calling-rates anywhere in the world, and (also forthcoming) full interoperability with other VoIP networks and with the H.323, MGCP, SIP protocols.
WorldVOX has launched its own soft-phone called Firefly, which is completey free for download right here.
I have dome some limited testing with FireFly already and it does work as advertised. Voice quality is very good also on fast dial-up lines with an overall bandwidth use of less than 50-55 Kbps. Frequent audio breaks and packet loss is to be expected on voice sessions with an available bandwidth of less than 50 Kbps.
FireFly offers full duplex voice communication with no hiccups and completely hands-free.
Among its unique abilities the FireFly soft-phone can work through NATs and firewalls with greater ease than existing VoIP solutions and a slew of other great features including:

Security of number and call
Portable and interchangeable phone number
Graphical navigation in handset
Fully featured Voice-mail service (digital answering machine integrated!)
512 encryption engine
Can be tailored for different languages
Long distance carrier interfaced in to handset (coming soon)
Can work without a sound card
Operates without Gateway
Operates through most Firewalls
Echo Reduction
The tools is free from spyware and does not install any malicious software on your PC.
To find out more about the national/international calling rates that will be charged to those who want to call standard telephone lines from their PC here is the page to look at.
Free download of the tool here. (Beta version)
Important notice: In case your Firefly doesn't work right out of the box follow these simple steps.
To make your Firefly work, register yourself and get a phone number. Once the tool is installed right click on the Firefly icon in the system tray, and select Options. Then click on Networks and select Network 1. In there type again your number and password. You are now ready to work.