I see Web 2.0 as the Intelligent web or ‘Harnessing Collective Intelligence.' Mobile Web 2.0 extends the principle of 'Harnessing Collective Intelligence' to restricted devices. The seemingly simple idea of extending Web 2.0 to mobile Web 2.0 has many facets, for instance:

a) What is a restricted device?
b) What are the implications of extending the web to restricted devices?
c) As devices become creators and not mere consumers of information – what categories of intelligence can be captured/harnessed from restricted devices?
d) What is the impact for services as devices start using the web as a massive information repository and the PC as a local cache where services can be configured?

 
Restricted devices: A broad definition of a ‘restricted device’ is not easy. The only thing they all have in common is - ‘they are battery driven’. But then – watches have batteries?

A better definition of restricted devices can be formulated by incorporating Barbara Ballard’s carry principle. Thus, a restricted device could now be deemed as: 

a) Carried by the user
b) Battery driven
c) Small (by definition)
d) Probably multifunctional but with a primary focus
e) A device with limited input mechanisms (small keyboard)
f) Personal and personalised BUT
g) Not wearable (that rules out the watch!). But, there is a caveat, a mobile device in the future could be wearable and it's capacities may well be beyond what we imagine today. The input mechanism in the future will not be a key stroke on such devices, but a movement or sound. So, this is an evolving definition.

Finally, there is a difference between a ‘carried’ device and a ‘mobile device which is in a vehicle’.

For example – in a car, a GPS navigator is a ‘mobile device’ and in a plane, the in-flight entertainment screen is also ‘mobile’. However, both these devices are not ‘carried by a person’ and do not have the same screen/power restrictions as devices that are carried by people.

However, whichever way you look at it, it's clear that the mobile phone is an example of a restricted device. From now on – we use the definition of mobile devices interchangeably with ‘restricted devices’ and the meaning will be clearer in the context.

Extending the web to restricted devices:  It may seem obvious - but Web 2.0 is all about the ‘web’  because Web 2.0 could not have been possible without the web. Thus, in a ‘pure’ definition – Web 2.0 is about ‘harnessing collective intelligence via the web’. When we extend this definition to ‘mobile Web 2.0’ – there are two implications:

a) The web does not necessarily extend to mobile devices
b) Even though the web does not extend to mobile devices, intelligence can still be captured from mobile devices.

The seven principles of Web 2.0 speak of this accurately when they discuss the example of the ipod/iTunes. The ipod uses the web as a back end and the PC as a local cache. In this sense, the service is ‘driven by the web and configured at the PC’ but it is not strictly a ‘web’ application because it is not driven by web protocols end to end(ipod protocols are proprietary to Apple).

Thus, the characteristics(distinguishing principles) of mobile Web 2.0 are:

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

Another way to look at this idea is to consider what is NOT mobile Web 2.0. ‘Broadcast’ content generated by the media industry which users are passively expected to consume: is not mobile Web 2.0. That includes most ringtones, most games, movie clips etc. Anything which does not have a user generated component. Of course, I welcome your comments on this topic.

 
Restricted devices: A broad definition of a ‘restricted device’ is not easy. The only thing they all have in common is - ‘they are battery driven’. But then – watches have batteries?

A better definition of restricted devices can be formulated by incorporating Barbara Ballard’s carry principle. Thus, a restricted device could now be deemed as: 

a) Carried by the user
b) Battery driven
c) Small (by definition)
d) Probably multifunctional but with a primary focus
e) A device with limited input mechanisms (small keyboard)
f) Personal and personalised BUT
g) Not wearable (that rules out the watch!). But, there is a caveat, a mobile device in the future could be wearable and it's capacities may well be beyond what we imagine today. The input mechanism in the future will not be a key stroke on such devices, but a movement or sound. So, this is an evolving definition.

Finally, there is a difference between a ‘carried’ device and a ‘mobile device which is in a vehicle’.

For example – in a car, a GPS navigator is a ‘mobile device’ and in a plane, the in-flight entertainment screen is also ‘mobile’. However, both these devices are not ‘carried by a person’ and do not have the same screen/power restrictions as devices that are carried by people.

However, whichever way you look at it, it's clear that the mobile phone is an example of a restricted device. From now on – we use the definition of mobile devices interchangeably with ‘restricted devices’ and the meaning will be clearer in the context.

Extending the web to restricted devices:  It may seem obvious - but Web 2.0 is all about the ‘web’  because Web 2.0 could not have been possible without the web. Thus, in a ‘pure’ definition – Web 2.0 is about ‘harnessing collective intelligence via the web’. When we extend this definition to ‘mobile Web 2.0’ – there are two implications:

a) The web does not necessarily extend to mobile devices
b) Even though the web does not extend to mobile devices, intelligence can still be captured from mobile devices.

The seven principles of Web 2.0 speak of this accurately when they discuss the example of the ipod/iTunes. The ipod uses the web as a back end and the PC as a local cache. In this sense, the service is ‘driven by the web and configured at the PC’ but it is not strictly a ‘web’ application because it is not driven by web protocols end to end(ipod protocols are proprietary to Apple).

Thus, the characteristics(distinguishing principles) of mobile Web 2.0 are:

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

Another way to look at this idea is to consider what is NOT mobile Web 2.0. ‘Broadcast’ content generated by the media industry which users are passively expected to consume: is not mobile Web 2.0. That includes most ringtones, most games, movie clips etc. Anything which does not have a user generated component. Of course, I welcome your comments on this topic.