Handheld Learning - learning with mobile and ubiquitous technologies

Hi,

I work for a Programme and System Assurance company who, as part of thier work, provide learning solutions.  My particular job is to identify learning needs and suggest a cost effective way of meeting those needs.  The use of heandheld technology is clearly an option to meting those needs and to that end I have just produced a framework that allows you to compare different solutions and come up with a rational answer taking into account the affordances of mobile technology/learning (that's the theory at least - if anyone wnats to try it out pse let me know).
I'm also studying for a Masters in Education, Technolgy and Society at Bristol University, whch is where I heard about handheld learning.
I can be contacted on steve@shartley.freeserve.co.uk

What is not taken into account is the 'cost' of supporting this technology in school.  As someone who was a school Governor when we introduced a ICT Suite you suddenly realise that you need additional skill sets within the teaching staff, and if they don't exist, how they will be bought in or provided.
As part of an MSc I am trying to develop a framework that will assist in this decision making progress - is it cost-effective in education/training terms to introduce this new technology.  What are the factors that have to be considered when trying to decide if to move to this new technology, and if you had an online tool to help you would you use it? (My current list extends to at east 25 different factors ranging from the social/cultural aspects to the technical aspects.)