If you use Skype, or have thought about using it, you might want to check out Gizmo. It’s an open source alternative to Skype (as Firefox is to Internet Explorer), and seems to have some interesting features. One is that the group behind Gizmo is offering free Gizmo-to-phone service. That is, you can call people’s landline or cell phone for free (from your computer, via Gizmo, assuming your computer has speakers and a microphone—either of which can be picked up for $15-30 if you need one), provided you are both Gizmo members. Membership is free. Skype has a similar feature, but last I heard you have to pay by the minute for it, just as with regular long-distance calling.