Crunchgear has a tip that the low-end Treo 680 may be launching on Cingular for free, but with a catch. Apparently Palm's lack of carrier announcement during their Treo 680 launch apparently was due to problems trying to find a carrier who will carry the phone.
Cingular seems to be a likely candidate, subsidizing the 680 down to a skeletal $0, but requiring you to sustain a $30 internet plan for the entirety of your two-year contract. T-Mobile may also be a contender, but wants WiFi on the Treo in order to pimp their hotspots or work with their upcoming home VoIP program. Either way, Palm had better work fast to get these into the hands of consumers.
Possible Treo 680 Launch Plans [Crunchgear]