How about an interface where players can ask for loans and other players can fill them, kind of like people do on the forums now.
Imagine a list of unfulfilled loans with progress bars for the amount asked for, specification of the percentage return etc. Players lend money and the money becomes unlocked to the recipient once the loan has been fulfilled and locked for the lender for the amount of time the loan was requested for.
Players can build up a reputation bar to prove themselves legitimate. The payments would be automatic, taken care of by the interface, and maybe there is a mechanic that allows players to run off with the capital or something to spice it up, I’ll leave that for discussion.
I personally want the idea as I don’t have much time to play, and really do not want to spend any of my time playing to earn ISK, I just want a way to earn ISK to PVP. On the flipside I imagine this system would work nicely for traders of all levels because it seems like finding investment on the forums is a real pain, and maybe players that need a quick boost for whatever reason could also find a way to use the system.