I know that there are margin trading platforms for the Bitcoin/currency exchanges, but would anybody be interested in one for the GLBSE? I've been working with the GLBSE API lately, making a couple trade bots (I've turned them off for now, to ease the load), and I think it would be fairly straightforward. Basically, I would just provide an interface to allow people to borrow and trade on margin accounts, but controlling the withdrawal so that they can't just abscond with the money. What do you all think?