We've done it. A couple hints:
- I packed up a "sample box" of clothes and took it to UPS for an estimate. It was cheaper, though not much, but it made traveling a little easier -- no suitcase to wheel on/off the plane, no need to fight for overhead space. It'd be especially nice for a person who had a layover/need to change planes.
- I mailed the package a good week in advance, and I called the hotel to verify they'd received it. This won't do for a last-minute packer.
- We chose carefully: We wore our boots and mailed our flip-flops.
- No problems with liquids. I did encase everything in ziplocks.
- I packed a half-used roll of packing tape with my clothes so I'd be able to re-package the box at the end of the trip.
- Obviously, you can't mail the suitcase (or even a duffle bag) if you want to save money -- you have to mail just the clothes in a box.
- It was cheaper going home because our toiletries, sunscreen, etc. didn't make the return trip.
- Yeah, Southwest doesn't charge for bags, but we don't have Southwest here.