A technique implemented by the team was using FirstSortedValue() and a Data Island of field names to allow the user to select fields they wished to view in a chart object. Details on how to use FirstSortedValue() as a customizable straight table can be found here http://community.qlik.com/docs/DOC-6046
This proof of concept uses a VB_Macro to change the sort-weight which is contained in an InputField.
I'll write a more detailed instructional document on my blog soon. jason.michaelides also has a community document on the subject which I'll add a link too shortly
I hope you find it useful and look forward to hearing your comments.