GSM - watch VoIP--James Seng in Singapore has a post about GSM, WiFi and VoIP. He quotes Mike Mulica CEO of Bridgeport Networks. If you are not familiar with Bridgeport they have some of the smartest guys in the crossover biz involving Mobile and VoIP.
I keep watching this company closely and am never amazed by what they do, because they are the kind of company you want expect them to do great things. Between their Management team's background and the technology they are creating plus their insight, makes them idea experts in the convergence space.