"Gizmo Project uses your internet connection (broadband or dial-up) to make calls to other computers. With the click of a mouse, you’re connected to friends, family, and colleagues anywhere on earth. It’s just that simple. You talk clearly. For as long as you want. For free."

What's New in v3.1.0.218 (since the release of v3.0.0.206):

• Added support typing indicators so you can see (and other can see) when each person chatting is in the process of typing.
• Added a built-in crash reporter for reporting problems directly to SIPphone.
• Added a new multi-user chat invitation window that is used when creating/joining/inviting.
• Added recognition of AIM, MSN, and Yahoo contacts for easily adding to your contact list.
• Added recognition of non-gmail.com GoogleTalk contacts when adding to your contact list.
• Added print and delete toolbar button to the chat history window.
• Added an optional print button to the chat window.
• Added 'Invite to Group Chat' menu items to the chat window participants list.
• Added menu options and command-key equivalents for selecting next/previous tabs in the chat window.
• Added support for version upgrades using the Sparkle framework.
• Added support for embedded linefeeds in chat messages.
• Added support for showing the current track name and artist from iTunes.
• Refreshed the user interface with new icons.
• Moved the 'Send Instant Message' elements into a separate window so they're not tied to the main window.
• 'Invite to Group Chat' menu items will filter out known participants.
• Changed 'reopen' behavior so the main window is no longer focused if other windows are open.
• Changes so the chat window will stay open even if you logout of your current session.
• Restored functionality to allow a call to be terminated by pressing the escape key.
• Pressing return on a contact or call list item will now call or instant message depending on what the default action is.
• Improved matching by phone number for incoming calls.
• Fixed a bug that did not correctly show dock notification if the chat window was not focused.
• Fixed memory leaks that occurred when closing tabs in the chat window.

Full Press Release Gizmo Project (Homepage)