I'm doing one of those Delta Singapore mileage runs just over a month and since I expect to be changing planes pretty often, I figured I would just use a smaller carry-on bag for the clothes I'd need to take on my trip. Which means I'd likely be checking in nothing on my own. But why not carry bags or boxes for somebody else across the pond? I was thinking of posting something to CraigsList saying "need something transported from airport A to airport B?" for some reasonable amount, with the caveat that I get to thoroughly inspect what's in the box before sealing it and taking it to the check-in counter. Now the chances of me actually doing this are super slim - since I'm guessing there are still security concerns, most people won't trust strangers to actually vouch for their baggage and of course if I sense there's anything sketchy about the people I'm talking to I wouldn't end up checking their bags/boxes in either. But I remember those "be a courier!" ads from when I was younger and thought it might be a bit of a possibility. What do you think? Completely stupid or a (very slim) possible way to cut the cost of a mileage run a bit?