Hey guys,
Some options, one of which was already mentioned, are being teachers... You can be a Substitute Teacher here in the DFW Metroplex for somewhere around $75.00 to $100.00 a day... All you need to do is pass a background check (which I'm sure an airline pilot can easily do) and you're set to go... Some school districts require a two or four year degree and some require none at all. But remember how you treated your subs when you were a kid and think long and hard about this one. To be honest, the kids you'll be teaching are much like senior airline management that you already deal with... They'll take advantage of you and try to convince you that they're doing you a favor. Hee, hee...
Second, contact your local community college and talk to department heads about being Adjunct Faculty. In this case, you generally teach a class one night a week for the semester, and the pay was about $1500.00 per class, per semester. I once taught a couple of classes and it produced about an extra $1000.00 a month. It was easy and I really, really enjoyed it.
The only other option I have been contemplating is submitting a resume to the Medallin, Columbia drug cartels... There is no sim ride, (though this is where your commercial maneuvers like turns around a "drop spot" will really come in handy) and they wont alert your current crew scheduling to the extra hours you'll be flying. I'm kidding of course.
Good luck and big bucks!
Jason