I'm still waiting for my Vonage hardware to get here… then I'll be VoIP happy. I've used Skype at times in the past, but apparently – it's not the same as the direct kind of VoIP. We've already set up an “official call-in” software page on Lockergnome Downloads (Firefly). And for those out there who are still trying to escape the clutches of your phone company, here's the first part of Wikipedia's definition:

IP Telephony, also called 'Internet telephony', is the technology that makes it possible to have a telephone conversation over the Internet or a dedicated Internet Protocol (IP) network instead of dedicated voice transmission lines. This allows the elimination of circuit switching and the associated waste of bandwidth. Instead, packet switching is used, where IP packets with voice data are sent over the network only when data needs to be sent, i.e., when a caller is talking.
Its advantages over traditional telephony include:

• lower costs per call, or even free calls, especially for long-distance calls
• lower infrastructure costs: once IP infrastructure is installed, no or little additional telephony infrastructure is needed
• new advanced features
• future proof as functionality is software (protocol) based and does not require hardware replacement

Voice over IP traffic does not necessarily have to travel over the global Internet; it may also be deployed on private IP networks for example on a LAN inside a single building.
The protocols used to carry the signal over the IP network are commonly referred to as Voice over IP or VoIP protocols.

I've heard good things and bad things about VoIP, and will definitely be keeping an eye on this particular VoIP forum (with its feed).