Lots of good suggestions here, and I've considered all of them. Solid perfume will end up being the easiest of all I think, as I don't even have to think about it. Now all I have to do is find one that I like. The only one of my usual perfumes that comes in a solid is Jean Patou's Sublime. Gwen Stefani and Sarah Jessica Parker have ones that sound (on paper) like I might like them. I'll be visiting Sephora in the near future.
As for the other options, the drawbacks are...
1. Samples: only available for some perfumes, typically (though not always) those that are recently released. The only one that I could find of my usual perfumes was Chanel's Chance.
2. Purse-size atomizers: Sephora's got several of these that would suit, but the problem is getting the perfume out of the original bottle, as I typically buy atomizers. So this option is only available for atomizers that can be opened (the only one of mine that worked was Thierry Mugler's Cologne) or for those products that are available in non-atomizer form (and then I'll have to buy those separately). Dior's Tendre Poison, Chanel's Chance, Patou's Sublime, and Burberry Brit all sealed in such as way that they can't be opened for decanting into another container.
3. Lotion: not always available in the desired scent, and typically require using a larger volume, so not ideal for compact packing. Not always the same scent, I find: I much prefer Dior's Dune lotion to the actual perfume/cologne, for instance.
4. Ignoring the 1 qt ziploc bag rule: nope, not going there. I've had screeners miss or ignore all sorts of stuff that I've inadvertently left in bags, but that doesn't mean that they won't object the next time I'm at TSA. I'm a follow-the-rules sort of person, and bending them would make me so anxious I'd likely be pegged as a cocaine mule.