Yeah, I second that...

I think it's a matter of mindset. You have time, you do something that makes you money...

You can just say it to yourself.

"Hey Halfswede, Paris is only $325 r/t this week...I need some croissants!"
"Hey Halfswede, Seoul is $469! How about some Kimchee?"

Seriously though, if you sign up for weekly fare alerts from Travelocity and Expedia and as many airlines as you can, you can find some amazing bargains.

Also, you could look into courier flights. I don't know too much about them these days, and IIRC they were usually 7 day fixed tickets, but you could schedule a week off and then see where the tix are available.

Other thoughts are:
-Repair technician for some obscure type of equipment
-Drug Mule
-Highly specialized work in some field like lawyering, financial advising etc.
-Double-0 type secret agent.
-European rep for a large, highly regarded hot sauce maker
-Masseur to the stars - "available with 24 hours notice to Paris, Rome, Milan and Monte Carlo."