Erica Sadun reports that hacker eok has successfully ported SvSIP (a VOIP solution using the SIP protocol, written by Samuel) to the iPod Touch. This is a big step! Of course this means iPhone as well, if not with the exact same version, perhaps a slightly modified one.
AT&T won't be too happy about this one... VOIP will allow unlimited calls while on WiFi. Of course, this is still in development, so a polished app is a bit off, depending on how quick they work on it, but this is a huge step.