In case you didn't read the thread in the Aviation Photography forum, there is a proposal floated about to charge for downloading of photos on this site. I don't want to restart that discussion as it has been covered quite enough, but in his last message, Johan mentioned that he was open to OTHER suggestions as to how to make money besides ads.
I would like to suggest, as a first step: how about voluntary contributions? Some may laugh, but I and probably many other airliners.net users would probably be willing to contribute maybe $10, $20, $50 or even more per year, since there seem to be a lot of enthusiastic people here. Would people be willing to pay?
I had posted a suggestion about the Amazon Honor System, which lets web sites do this but no one seemed to reply. It's only available in the US currently, but someone in the States could volunteer to collect payments, and forward them to Johan when there is a sufficent amount.
Another suggestion is Paypal, that is available to Swedish residents.
Also, Johan, since you are a student, I assume you will be losing the University's hosting of airliners.net when you leave. Do you have any plans as for what will happen to the site after the inevitable happens, or is that still very far off in the future?