If you’ve never been to FlyerTalk, I’d highly recommend a visit. The website has become the main virtual gathering place for the frequent fliers of the world. There are dedicated forums for each frequent flier program as well as some more general forums.
As you may have guessed, frequent fliers are very unhappy at the prospect of having to check a bag, so they’re coming up with some pretty creative workarounds in this thread as well as others.
Seems like the thread starter had been able to find non liquid substitutes for all his toiletries with the sole exception of toothpaste. Sure enough, there were a few responses right away suggesting everything from “pre-pasted disposal toothbrushes” to plain old baking soda.
I know personally that for shampoo that you can buy things that look like a bar of soap. Stick deodorant is fine as well. Shaving cream, well, I haven’t figured that one out yet unless you’re willing to do it with just water. Ouch. And if you need makeup, well, you’re on your own there.