For what it's worth, the Fallen Brigade already does this, nominally under my control as a pet project that started in mid January 2012. It has been a resounding success, so long as our Bankers are active; this hasn't been a big problem, though.
It is NOT that hard to do without a system in place, but it would certainly be far more convenient to havesuch a system for managing a pool of assets, allowing certain members access to the general fund. Something like a tax-free mini-market inside a clan would work too, making trading easy. The Fallen Brigade just has a few specific, low cost items that we use with imbalanced trades. It's effective, but inefficient and tedious.
Anyways, I'd strongly support this sort of thing, but where there is a will (and trust) there is a way.
