According to eWeek, Linspire (aka Lindows) has released a new version of GAIM, the open source IM client for Linux (also available in Windows flavors). PhoneGaim couples IM services with VoIP:

PhoneGaim also lets you make phone calls to regular telephones, with your Buddy List, which means Linspire computer users just got a free pass to worldwide calling!

KEY FEATURES:

• Digital quality phone calls
• PhoneGaim to PhoneGaim phone calls are always free
• Free voicemail to email
• Free phone number
• Set-up a virtual phone number (premium option)

Slashdot notes that since PhoneGaim is open source, won't be long before we'll see a Windows client.