ok, here is a compilation of ideas for the beginning of a \'banking\' system, but remember, this should change, for the most part, and should be easy to start (not much work for model and what not...)
1.) An NPC that handles all transactions...
2.) A Building/NPC in each town/major area you might need one... (i say building/NPC because they could just put an NPC outside with a box for all i care, and if it were a wizard, it could be easily explained)
3.) A courier system that can send/recieve items from any town, for a small fee (i say send/recieve, because i think it\'d be nice to be able to retrieve items when you get to a town, just incase you forgot to send them) this one could be replaced with magical wizards for bankers, and there could be no fee (good idea for initial setup)
4.) The abilite to access the bank with other characters of yours, provided they are on the same account (you should only have one anyway, but some people do not honer that), not just the character that deposited it, though there should be a *small* fee for accessing other chars accounts (like 20trias)
5.) The ability to post items/search for items for sale, w/o the person being online
I Believe that this could be done, but i highly doubt it could EVER be done with player or a guild, but if accomplished, i would have alot of respect for the players able to do such...