It seems to me that individual shareholders will rarely exercise their voting powers because of the difficulties in attending AGMs. As proposed in the previous post, voting via the web, utilising Interactive Democracy, could be a solution. Another idea is to allow the creation of Shareholder Unions. Such a Union may have the perennial objective of limiting super-salaries with voting power commensurate with the number of shares held by all their members.
The practical problem with such an idea is How do you register voting rights when shareholders frequently trade their shares?
One solution is to make it mandatory that pension and Individual Savings Accounts providers integrate their share accounting with a central system able to apportion votes. This sounds much more complex, and expensive, than the one-person-one-vote Interactive Democracy system proposed here.
Another solution would be for pension and ISA providers to offer their commitment against super-salaries, perhaps utilising it as a unique selling proposition in order to stand above their competitors.