Ajit Jaokar at Web 2.0 Journal distills the defining characteristics of Mobile Web 2.0 down to the following:

a) Harnessing collective intelligence through restricted devices i.e. a two way flow where people carrying devices become reporters rather than mere consumers

b) Driven by the web backbone – but not necessarily based on the web protocols end to end

c) Use of the PC as a local cache/configuration mechanism where the service will be selected and configured

I think these sum it up very well – especially the emphasis on the phone as an input mechanism.  Ironically, it seems that in the US, the only carriers putting this power in the users’ hands out of the box are MVNO’s.  Helio’s MySpace integration for example.  Nokia tried to do it right from the factory with their LifeBlog package, but that hasn’t taken off at all here.

Will the major carriers try to establish relationships with Web 2.0 companies?  What if Cingular integrated with Flickr on all their phones and provided a special discounted data plan to upload and view photos?  What about a Verizon EBay plan for those crazy sellers and buyers out there.  Run around your garage and post to EBay from your phone!

Are these carrier-sponsored Mobile Web 2.0 services a good thing?  Some would say it’s another attempt at sandboxing, but I think the mass market needs spoon-feeding like this in order to bootstrap more sophisticated use.